In its latest ranking of affiliate marketing firms, topseos.com, said that hundreds of vendors were "scrutinized in order to put together a list of the best affiliate marketing services." "It can be difficult to find a quality affiliate marketing program management company," the company said. "The industry is full of companies that promise results and conversions, but which ones deliver the quality results is a lot more difficult question to answer." topseos.com identifies companies as the best based on five keys areas: network, implementation, monitoring, reporting, and optimization, it said. Additionally, the company said it contacts clients of the firms to find out more about the inner workings of the companies, such as reporting frequency and transparency, use of analytics and need assessment and change implementation. Among the companies top 10 affiliate marketing firms for January 2010 were, Experience Advertising, Paulson Management Group, NETexponent and Affiliate Marketing. The company, which has been evaluating affiliate marketing firms for eight years said it has reviewed 3,000 firms in 130 countries in developing the criteria used for the listing.