@asksqn There is surly something to your angle but I see this issue of invitation a little differently. There is something odd and arrogant about this "invitation" method that Google employs. My earlier comments have been tongue and cheek, as this Google oddity surfaces every time they launch a new offering.
Brilliant marketing to the masses ? Maybe. But I think most outside tech circles don't even know about it. This makes the method even more odd if you ask me.
I have known only one person who actually received an invitation for an as of yet unveiled product offering by Google. I can't recall how he got it in the first place though.
So I just chalk this up to " it's Google's World, we just live in it ".