Prices for display ads sold through ad networks dropped for the second quarter in a row, reaching the lowest price this year.

Display CPMs were $0.27 on average, according to PubMatic's AdPrice index, down 21 percent from the previous quarter, and 27 percent for the same quarter last year. Ad network rates fell in nearly every content category, including social networks, news, entertainment, business and gaming. Technology websites commanded the highest CPM ($0.57), and tech was the only content category that did not experience a decline.

While display is seemingly on a downward spiral, some argue that it has the potential to come back strong. The silver lining to all the gloom and doom is that sites with traffic under 100 million drew CPMs of $0.61, close to three times what big publishers with more than 100 million views were drawing.