Hi - there's no one single place to ask questions related to Adobe products, such as; SiteCatalyst, Test& Target, Discover etc. It would be VERY useful to ask/answer questions with other Adobe product users which in turn would mean fewer client care requests for Adobe.
I believe the Adobe Community forums is the answer but I don't think many people know about it because there's very little activity. My suggestion would be to have links in the footer and other prominent places of; SiteCatalyst, Test& Target, Marketing Cloud, Help section, ClientCare etc for promoting the forums which should hopefully create a proper community where customers can discuss ideas and help each other with issues.