maximillianos - 6:04 pm on Oct 31, 2010 (gmt 0)
We use both. We have certain ad units that are only text ads. And we have certain that are image only ad slots. They both do well. Text ads overall do better I think because typically they offer more options to the user, and there is no interpretation needed. They say what they are offering. Image ads need to often be interpreted. Especially animated ads that take a few seconds to unfold what they are trying to sell.