1) incredibly poor rollout strategy (imo)
2) what problem did it actually solve again?
forgive any appearance of snark; i just wanted to be concise, and i don't think that "the ideal marriage between email and IM" is something that people were - or are - desperately crying out to have.
I believe it failed in part because of the slow rollout (nobody you cared about had access yet) and lack of interop with email for notifications about changes, etc. I tried using it, and gave up. By the time it became widely available most of the early adopters gave up as well.
forgive any appearance of snark; i just wanted to be concise, and i don't think that "the ideal marriage between email and IM" is something that people were - or are - desperately crying out to have.