Online affiliate marketing spend $3.3 billion in 2012

It’s not common to see affiliate marketing studies so caught this one on Shawn Collins AffiliateTip.com blog. Jupiter Research published the US Online Affiliate Marketing Forecast, 2007 – 2012.

As Shawn reported – JupiterResearch has published a study on affiliate marketing that indicates online marketers will spend $2.1 billion on affiliate marketing fees, with US online affiliate marketing spending reaching $3.3 billion in 2012.
I am not clear what that means… “affiliate marketing fees”? I presume that is the aggregate cost of running an affiliate program: affiliate network fees, affiliate commissions, etc.
According to the report, affiliate marketing remains a highly attractive endeavor because it is performance based, presenting low risk and requiring low initial investment. Over time, marketers tend to work with affiliates that drive the most traffic to their sites, resulting in a small number of affiliates driving the majority of traffic and sales. Because affiliate marketing is so heavily intertwined with the search engine marketing industry, Google is the one wild card that might affect the overall growth of the industry. Google’s dominance over SEM forces affiliates to be sensitive to Google’s Quality Score, which prevents lower-quality affiliates from buying paid search.

After reading this I also have a similiar question in what constitututes affiliate marketing fees. This report sends a strong message to states like NY that revenue is being driven through affiliate channels and would like to see more detailed data by segment. I am sure that Patti Freeman Evans who wrote the report will be able to shed some more light on this at the Linkshare Symposium as Shawn noted. Personally, I am more interested in the $3.3 billion in 2012 and what the trend has been since 2000 on an annual basis and how they calculated it.