We've continued to see a lot of people visit from Tumblr, which is awesome!
There's been a couple common questions I wanted to try and answer for the wave of new authors who have recently arrived.
First, BetaBooks isn't a social network, it's web-based software like Google Docs, except specifically designed for authors running betas. Everything you do on the site is private, and then when you're ready to share you can invite your readers via email. In other words you bring your own readers. You can practice your queries on the reader directory if you're on one of our paid plans, but that's not a good primary source of readers.
Also, per our terms of service, BetaBooks makes no claims to your work, and because everything is private there's no impact on your publishing rights.
I hope this helps everyone who is new on the site, and thanks again! If you have any questions we're easy to reach, just shoot us an email :)