The article is from 2009. The graph shows online ad rates halving over 2008. How much of that is a long term trend, and how much of that is because of the reces

The article is from 2009. The graph shows online ad rates halving over 2008. How much of that is a long term trend, and how much of that is because of the recession? (Though this doesn't detract from the rest of the article, which covers alternate business models.)