Forum Moderators: skibum
Though this is a generalization, and there are always exceptions, most of these types of sites have a hard time making more than their hosting costs. There is no targeting, there is no special area of interest or niche, so the basic value is sending a branding message. CPM banner sales are rock bottom, and often the (cost of) bandwidth used outweighs the revenue.
For example, gaming and celebrity sites have lots of large images that kill their bandwidth, and few users that are of value to advertisers.