Many private betas receive plenty of participation, but that isn't always the case. Some proposals simply go too long in the Commitment phase, so folks forget and find other things to do.
Private betas are anything but private, they could technically be called 'mostly closed betas' instead. It's easy for anyone to see what's going on in a private beta by simply using our API. We opened them up a bit more by letting people join provided that they found the proposal on Area 51 - even if they didn't commit. This ensures that:
- Anyone arriving to the site is probably interested in building it, and knows it's a work in progress.
- Noise from the outside world is still mostly kept in check, allowing new communities to get down to business and have the discussions that need to take place during this early phase
- Potentially great contributors that might not have committed simply because they didn't notice the proposal in time aren't alienated
- The site stands a better shot at entering public beta quickly
As you noticed, you had to log in, anonymous traffic can't find their way into a private beta. Before we did this, users just had to find someone they knew that had committed to send them an invite link via email, it just made sense to let anyone logged in and interested enough in the topic to get in.
This has worked pretty well so far, and while I haven't run the numbers yet, Software Recommendations had an amazing turn out, some of which might be attributable to this change.