GMail's invite-based beta worked because there were no network effects in the product's value proposition. Even if those with whom I frequently corresponded di

GMail's invite-based beta worked because there were no network effects in the product's value proposition. Even if those with whom I frequently corresponded did not use GMail, I benefited from the product. Wave was totally different -- everyone with whom I wanted to collaborate (at least in a particular context) had to have accounts, and I didn't have that many to give out. The product should have been implemented so that email/IM/whatever were used as fall-back "protocols" for those who had not yet adopted Wave. Also, the invites should have granted one the right to create N waves involving, say, 50 people max.