I’ve been in the computer telephony game for a while. I launched my first startup in this space, InterGalactic Research, in 1995. We had a product called iPost, one of the world’s first Internet-based unified messaging platforms. iPost combined a Google Voice-like phone interface, a Gmail-like web interface, plus everything that eFax does and you could even send notifications via SMS to your favorite mobile devices. Pure messaging bliss.
People loved it. Carriers, infrastructure providers, telephony card makers, text-to-speech providers, everyone loved iPost. We secured investors in short order, we announced a partnership with Ericsson, licensed it to Motorola, won Info Magazine top 100 awards, cover of Home Office Computing magazine, we’d made it big.
But we were also frustrated. We realized how insanely difficult it was to make computers talk to telephones. Back then they called our industry ‘Computer Telephony Integration’ (CTI). We thought, hey, if a few kids in a garage Central Florida could be this disruptive to the entire communications space, why not move out to Silicon Valley and do it even further?
So we did.
In 1999 we launched Voxeo. Instead of building a specific CTI application (like iPost), we wanted to build a platform that let any developer build any telephone application. We created a super-simple, XML-based telephony language (here’s a document about CallXML from 2001 that describes it), raised initial funding from a very high-profile group of Angel investors, (including now-Google-Chairman, Eric Schmidt) and later did a high-profile VC round with Mayfield and Crosspoint. We invested most of that money in R&D and building a broad developer community. Soon thousands of developers were signing up every month.
Now the Voxeo and Tropo community boasts over 250,000 developers. Voxeo is employee-owned, global, profitable and can call half of the Fortune 100 our most important customers. I’m not saying this to brag (well, maybe a little), but I prefaced all of this by saying, “I’ve been in the computer telephony game for a while.” Back in 1999, I was Voxeo’s Vice President of Community Development, now they call me a Chief Evangelist.
I’m telling you all of this because, by the title of this post, you’re probably wondering why I say “Twilio looks better from afar”. I’ve watched Twilio closely for over two years, since shortly after they launched. I’ve talked with current and former Twiliots (Twilions? Twilioers?), venture capitalists, telephony geeks, coders and Silicon Valley “insiders”. And I’ve come to a few certain conclusions.
Twilio is certainly a Silicon Valley darling, but like some darlings, they look much better from afar. Here are biggest three reasons why:
1. Twilio is Still Losing Money
This one is easy to explain. Twilio launched in 2009 with $1 million in seed money. Every subsequent round of funding they’ve raised always happens in Q4 (November or December):
Series A: 12/09 $3.7 million
Series B: 11/10 $12 million
Series C: 12/11 $17 million
For you math geeks out there, that’s a total of $33.7 million. It might also give us a good reflection of Twilio’s actual annual burn rate. My guess is that we’re going to hear some kind of announcement in the next month or two.
Basically it comes down to this: Twilio is going to have to convince investors to put in more money (my guess is they’re asking for somewhere in the range of $30-$50 million. Heck, it could be some insanely skewed SV numbers like $150 million, who knows?) Historically, investors who put money in a Series D round can already see the exit. It’s typically known as the “bridge” round and it only happens if existing investors are 100% gung-ho about an IPO or acquisition. Given the tech-IPO climate in the last year with giants like Facebook falling flat, that seems unlikely scenario.
2. Twilio is Losing Talent
Let’s face it, the face of Twilio is vastly different than it was 18 months ago. Danielle Morrill, Jon Sheehan, Stevie Graham and John Britton, all the most visible people who did the heaving lifting in Twilio’s early days are gone and have been quietly replaced with “telco industry insiders” like new Marketer-In-Chief, Lynda Smith of Nuance and Genesys and Euro-Marketing-Director James Parton of Telefonica. I don’t know about you, but when I see almost all of a company’s most public-facing developer evangelists leave within a year, it smacks of a core strategy change, one of replacing established mojo with a briefcase-wielding enterprise sales team with commission quotas.
Twilio has already experienced rapid growth. I’d say it’s probably not difficult for smart engineers to see the writing on the wall and they would rather take their chances at a new startup with exponential growth possibilities rather than one obviously at the ‘winding down’ phase of startups.
3. Twilio is Displaying Increasing Signs of Desperation
Last week someone called me to comment on a TechCrunch article “announcing” “Twilio’s biggest partnership yet.” This “announcement” caused quite a stir in the Twittersphere. I keep putting “announcement” in quotes, because in reality there was no “announcement”. As
communications industry analyst Dave Michels pointed out on his blog, Talkingpointz.com, to this date, no one at AT&T or Twilio can confirm any sort of partnership.
Another sign of desperation? Re-releasing old news. For instance, today Twilio just did a press release “renewed alliance with Microsoft“. What’s particularly meh about this announcement is that they already made the same exact announcement in May.
These are exactly the kind of things startups do when are trying to attract investment: leverage advertisement buying power to get fluff pieces written about them and re-hash old announcements to create fake buzz. No doubt, Twilio certainly knows how to churn the Silicon Valley hype machine, but when you start to peek behind the red curtain even a little bit, it starts to look full of fluff.
Even Twilio’s own biggest fanboy, Super Angel Dave McClure, agrees, “Last time I checked, you can’t even provision a phone on Twilio or AT&T’s service (or at least they are not allowing it). I am still waiting for the real disruption to begin.”
Well, Dave, we’re all waiting.


[...] developers in its Tropo dev community — more than Twilio does today. There’s also talk that Twilio has lost some key talent around developer relations, which could mute optimism about the [...]
[...] [...]
Hey Johnny,
I’m building an app at the moment which is built around Twilio but now I have seen Tropo it looks like there is some competition out there!
Hey Josh, thanks for taking the time to comment on the post. Would love for you to try out Tropo and let me know how you like it.
[...] has 200,000 developers in its Tropo dev community — more than Twilio does today. There’s also talk that Twilio has lost some key talent around developer relations, which could mute optimism about the [...]
Hi Jonny,
Full disclosure: I work for a communications infrastructure company, and we work with many service providers and enterprises looking to “web enable”…subtly different than application companies looking to leverage infrastructure when they have none (Twilio and Voxeo’s traditional customer), these are companies with deployed infrastructure looking to leverage web application companies. I have been approaching the problem of bridging the gap between web and established RTC channels, from a web developer perspective. To that end, I have been exploring with a simple web app that I have been integrating with various signaling channels, including JavaScript SIP stacks, as well as APIs from Twilio (currently at TwilioCon, where I built an app in their hack-a-thon), Tropos, TelAPI, and even my own company’s solutions. They seem equally easy to use, full featured, and great ways to bridge the gap. Outside of the non-technical differences you point out above, I am struggling to find tangible differences between approaches (technically speaking) that would lead to one or another. Perhaps you can shed some light on this.
Hey Reid-
Thanks for stopping by. You pose a good question, one that I’ve addressed on the blog before, but probably needs to be updated because it’s been a while and both Twilio and Tropo have had some changes and improvements over the past year. Here are my top 8 differences between Twilio and Tropo (as of 10/12):
1. SIP compatibility: I realize Twilio has just announced a SIP Beta. If you’re in the telecommunications space, you understand the importance of SIP as a protocol. Voxeo’s entire voice network is natively SIP, and Tropo talks natively SIP internally and externally since our launch in 2009. The question here is really only relevant if you have an use-case that requires SIP (especially important for call-center integrations). Tropo’s SIP has been in production for 2+ years, and Voxeo rolled out SIP in 2001. Our SIP network has been hammered by developers, enterprises, call centers and just about every app you can imagine for over 11 years. Alternatively, Twilio announced their “Beta” SIP implementation just yesterday.
2. Web-RTC Support: Voxeo Labs launched our Phono SDK in October 2010, and were the first to demo Web-RTC support in February 2012. We have been extremely active in helping push forward the Web-RTC standard, with three Voxeo Labs engineers on the Web-RTC W3C working group. We think there’s a huge amount of potential for Web-RTC and certainly we were not surprised to hear Twilio announcing a Web-RTC beta yesterday.
3. Speech Recognition: Tropo supports automated speech recognition (ASR) in 24 different languages. Twilio does not support speech recognition in any language.
4. Text-To-Speech: Tropo supports Text-To-Speech (TTS) in 26 different languages, and when you count up the various male and female voices we offer, there are over 60 different options. Last I checked the Twilio docs, they only support male and female voices in 5 languages. This distinction is especially important for international applications, as the value of having phone numbers in lots of different countries is greatly diminished if your application doesn’t work in the native speaker’s language.
5. International Phone Numbers: Tropo has offered local numbers in 41 countries for a couple of years. Twilio announced their latest expansion to 40 countries yesterday, many of those countries are still listed as “beta”.
6. Skype Integration: Every Tropo application gets a (free) Skype number that you can call from any Skype client. You also get at SIP address, iNum phone number, Phono number and can assign local phone numbers as well. I know Twilio announced some sort of a new “free developer” program yesterday but I haven’t had a chance to play with it yet. But the last time I checked, in order to call into your Twilio app you either had to use a number+PIN, or pay for a phone number. All Tropo numbers are free for developers.
7. Tropo Scripting vs. Twilio REST: This is one of the most powerful differences and possibly the least understood. With Tropo Scripting, you can create an app, host it in the Tropo cloud and Tropo runs your script for you. You don’t need to run the code on your own machine or use another hosting provider…we literally run your JavaScript, PHP, Ruby, Python, or Groovy code in our cloud. However, if you prefer to work with your own web server, using a request-response model, we also offer a Tropo WebAPI model, which utilizes HTTP and JSON to communicate back and forth between your web server and Tropo. Twilio doesn’t really have anything like scripting, their API is closer to the Tropo WebAPI. Nice thing is that Tropo offers both.
8. Build Your Own Private Tropo Cloud: Tropo is completely open source. You can download a free version of Voxeo’s PRISM application server (which comes with Tropo as well), run it on your laptop and in short order be accepting SIP calls on your laptop. This also means you can white-label your own Tropo-like service and run it on Amazon EC2 or wherever. That’s because we built Tropo from the ground up so customers were not locked to Voxeo’s cloud. We’ve seen everything from people building private Tropo clouds in Pakistan, inside giant telco’s like Deutsche Telekom to building ad-hoc cellular networks in the middle of the desert. I’ve never heard of a single instance of Twilio running outside of their network. If vendor-lock-in is something that you care about, then this is big technical difference.
I hope that gives you some more clarity on some of the key technical differences. Always happy to geek out further if you want to deep-dive into the discussion further
+) Diggz
Thanks for the thorough response. Clearly it is a more of a competitive environment than I realized.
As a former Twilian with the track-jacket to prove it, I think you’re pretty off the mark. It’s true that a fair number of early employees have left, but this is common as a startup moves into the mid-stage of its lifecycle. Two of those you listed, Danielle and John Britton, left to do their own startups (Refer.ly and P2PU), while the others joined small startups as early employees.
I don’t think that those departures can speak to any serious decline at the company. Furthermore, many important early employees, including the three founders, are still there, and there has hardly been an exodus of engineering talent. And while I of course can’t say anything about Twilio’s finances, I will note that they are (or at least were when I was there) shared with the entire company on a regular basis, so the employees are well aware of what’s going on. If it were really bad, I think you’d have more than a few examples of a 150+ person company.
As a developer I’ve used both Tropo and then subsequently Twilio. Twilio has put way more effort in than Tropo at this point. The tools are better. Tropo needs some more love. I do like how tropo offers more means of communication than Twilio, but the experience is not as smooth.
It was weird to see John Sheehan leave, and kind of a bummer really. I think Twilio will live on, but whether it will be a colossal success or just another web startup is yet to be seen.
You make some good points, thanks for the article.
Interesting piece. I think everyone in the industry has always known that Voxeo has a good product and been around longer that Twilio. However, let’s give a little credit to Twilio’s marketing team for crushing it over the last two years. This is such a big industry that it is probably a good thing for Voxeo to have Twilio further educate the developer community of the possibility of integration with Telecommunication (voice, video, sms).
Looking forward to see how everything pans out. If they do end up taking another round of funding, their founders will be fairly diluted by this point. Thanks for sharing this post. Couldn’t ask for a better Friday morning read.
This was an interesting read. I think Twilio gets a lot of credit for making a splash in SIMPLICITY of developing APIs and making VoIP seem cool again. It’s caused all the “old timers” you reference to also take a look and say “gee, we should be doing that.” Including you guys
That said, all your points are true, and I question how long Twilio will be able to continue what it’s doing on it’s current path. They’ve also done the rest of us a huge favor in allowing us to figure out what’s good, bad and applicable to our own products. And they’ve gained ALL of us additional exposure to how cool telecom can be.
Here’s some other thoughts… Twilio recently announced they were doing 1.5 million calls per day.
That’s an interesting number. Some known facts about phone calls – they average about 3 minutes in most cases. There are plenty of reports about that, feel free to google “average phone call length.” Twilio is probably aggregating calls in and out so let’s assume an average cost of the call for $0.015 per minute.
So 3 x $0.015 x 1500000 x 365 days/year = $24,637,500. So they are bringing in a bunch of revenue. Got it.
Now let’s assume that Twilio’s getting outbound rates of $0.0065 average, since Twilio isn’t a CLEC so it’s all spend to bandwidth.com and others. Let’s also analyze that they just rented a million+ dollar office and are planning to staff to 100 employees who, let’s say, average $80k. Let’s also assume that payroll tax in SF + admin is about 25-30% for most companies on top of employee labor.
We’re now talking:
0.0065 x 3 x 1500000 x 365 = $10,676,250 phone bill
80000 + 25% tax x 100 people = 10,000,000 labor
1,000,000 office space
So that’s $21,676,250 in expenses, not including marketing.
So they are probably profitable. Of course their marketing has got to be expensive. By my estimates they are burning at least $100k a month on marketing.
Does it mean they can keep up this way? I don’t know. I know that my revenue estimates are high, since they are including incomplete, busy and unanswered calls in their estimates. I also know that they are under the gun for SMS spam and are gonna have to start hiring lots of lawyers soon. So, yeah, the 80k average price tag per employee is probably super low.
But the real key, which you’ve pointed out, is having to go back to the well for more money. Evan and Jeff can’t possibly have that many shares left after 4 rounds, can they?