How the system decides whether or not I can join a private beta?

Question

This question already fits my problem, but the answer doesn't.

I want to contribute in the Arduino private beta. The site says

This site is in Private Beta.
Everyone who committed to the proposal can participate. The site's Public Beta will begin soon.

I commited to the proposal on April, 1st. However I did not get an invitation mail. Also the statistics state, that

committed users

228 users committed
53.1% signed up for beta

So obviously other users haven't joined the beta, either. This leads me to my questions:

1. How does the system decide who can join a private beta?
2. Have about 50 % of the users simply not accepted their invitation?
3. How can I still contribute to the private beta or get a new invitation?

Thanks in advance!

Answer 1

Everyone who commits to the proposal receives an invitation to the private beta. Unfortunately, only 50% of the people showed up despite having committed to the proposal and being notified when we started the site.

Barring any sort of technical glitches, the most common reason users don't receive an invite is they do not finish registration by verifying their email address (or the email ends up in their 'spam' folder).

In either case, I resent the proposal to the address on your profile.