If people are comparing you to Yammer maybe you are pitching to the wrong audience? When I see your video I'm comparing you to Campire! Are you like Campfire?

On a side note: I tested you product a couple of months ago for my startup (campfire was too expensive for our use) and we finally choosed jaconda.im because they have the gtalk/jabber integration and it was a killer feature for us! We dont need to have a special tab or install another program. We keep our current workflow with one more contact in our list. My 2cents

Edit: i wrote basecamp instead of campfire