If they pull a Wave and only invite users in small groups it is doomed on arrival. This thing needs to be free and massively available like Gmail. Social is not like email - you need wide participation in order for it to succeed.
You have to submit an email address to request access. I'm wondering if they are using their gmail address book data to see which emails are connected to each other before handing out invites. So if 10 of my close friends and I (who all have each other in our gmail address books) request invites, we'd be more likely to all get accepted than interested individuals with no interested contacts.
That might be a smart way to ramp up.
Also remember that Facebook started out very privately, too.
If it gains any sort of traction there's probably going to be inevitable breakage due to the growing pains of adding potentially millions of users a day. It's hard to win in this situation.
Gmail can be successful regardless of whether or not your friends use it.
A social network is only as successful as the number of friends using it.
Facebook did well on this by opening up things campus by campus ensuring that all your friends in your university were all allowed to use it at the same time.
Gmail used to be infinitely better than everything else on the market. So closing it it off made it only more scarce and sought after than it already was. Now if plus is even finitely better than everything else, so that artificial scarcity will make it seem more valuable, is debatable. It's a rather risky bet Google has already lost once with Wave.
Yeah massively available like Gmail - I meant after it opened up from invite-only status.
Email is easy to bootstrap because any client can talk using SMTP. Social does not have a protocol - although that might be cool if it did so we didn't have the "all your data are belong to us" problems of Facebook and Google.
