In that case, we're hitting it out of the park - over 4 invites sent per user, but these invites convert at ~25%. There's also "k factor" (invites sent x conversion rate), and the interval between user #1 bringing on user #2 is also important... guess there are many ways to present virality :)
Here's something we didn't share in the blog post. It's some of the print outs we brought along with us to the interview. No reason not to share it I guess. It shows some graphs illustrating virality, connection clusters (just one of them) and revenue growth.
http://www.yogatrail.com/yogatrail-stats.pdf
Thanks for your supporting comment and good luck with your business! Besides the money more of an issue was possible distraction for us. We are 3 co-founders. For us all going there would mean several hundred hours of flight and travelling. So we made the decision to only send one person (after consulting with Y Combinator).
However we should point out that Sven & Alex were on stand by via Skype during the interview to answer any possible questions that might have come up.
... Sven here (sharing this acccount with Alex). I'm full-time on YogaTrail. Besides me there are 2 full-time employees (Drupal Developers) on board, plus we use lots of free development resources from BUZZWOO!, a digital agency I co-founded. I consider this a huge advantage compared with other bootstraped start-ups and it enabled us to actually produce lots of software. Other than the main website YogaTrail has a very successful facebook app (we use for content marketing), several mobile apps and a bunch of very cool tools we use for marketing and growth hacking.
True - I hope I didn't come across as bitter, overall this was an awesome experience and the people at YC are amazing. I actually do think that they can probably tell if a startup is a good one or not in a matter of minutes.
The bulk of our user growth is due to viral loops we've built into things - we're pretty much getting each new user to successfully invite another at this point. Unlike Yelp, we're very "yoga-centric", and while Yelp is all the rage in San Francisco, that's not the case in the rest of the world... so we don't think that Yelp will be the place people will use to find their yoga, especially their yoga teachers. One persons 5 star is another's 1 star.
That's not to say we're neglecting SEO; we're working on strategies to get more search traffic (and in many places we're doing very well with that) and convert it into registered members. It's just not our main and only strategy.
But the real answer is: we're planning a feature (not there yet) that will solve a big pain point for millions of people (getting the schedule of their yoga teachers at a glance), and which will provide an even better viral loop (yogis inviting their teachers, and teachers using our site for their online presence).
Hi, "YT Premium" has been live for a few months and is the main source of revenue (we've actually doubled revenue nearly every month since January). Ads are there too, but they just started and are making only a small dent in our budget :)