Comment by aufreak3

At the time wave came in, you already had email, twitter and facebook. I think it became one more thing to check. Given that it was supposed to be 21st century email, the fact that you couldn't switch to using wave instead of gmail is, I think, what didn't get it the adoption. If magically all your gmail were available and accessible via wave as well from day 1, we might all be waving now.

I know there were some dev attempts at bridging the two, but they were so lame as to be unusable as a replacement.

I did end up using it for some personal planning, a bit of group work within our company, etc. .. but it currently is still just "one more thing to check".