Ask HN: has the onsite feedback (button/form) concept failed?

It all started with getsatisfaction and uservoice (I think), and after a while there were like 20 startups in this field. I used to see those "Feedback" buttons on every site back then, now I don't see them that much. Zendesk doesn't even seem to support or advertise that mode, I've seen few uservoice integrations without it (with ordinary button in the footer). Off all those 20 startups I only see 2 that are more realtime chat oriented (olark).

OTOH, Uservoice seems to move from feedback/community to something more like help desk (where Zendesk was).

What is your opinion?