The current google email is still a beta version, so google needs to GRADUALLY expand its user base and can not afford the explosive registration. They need to test their servers distributed at different places and accumulate expertise.
I gave away the free registrations since:
1. I am an early member and almost everyone in my family or close friends now got invitations for gmail. I still have 9 invitation unused.
2.These people made great contribution to the forums and I like their posts, esp, Gu's music links.
I never post on this site, and thus no motivation for networking. But I like their posts.