When is it too much effort?

I touched upon this topic in my post yesterday about Podcasting, but I have been thinking about it more since. At what point do you spend too much effort on your web campaign that it starts to affect the rest of your campaign. Blogs, Podcasting, E-mail newsletters, volunteer databases, online donations, together this is all a lot of work. At what point does the effort put in exceed the return from that effort? At what campaign size is all this effort begin to go from red to black? How do you judge the online audience, and that audience's receptiveness to all these stuff before you engage in it? It seems to me that just diving in head first with all this stuff could eat up valuable resources and do serious damage to the entire campaign by focusing on the wrong tactics.