Bing has the most potential traffic after Google, however, the latter does not support affiliate links or bridge pages (landing pages, for your understanding, are as hard to get approved as writing a phenomenal science fiction). So, it is obvious that Bing is the most reliable traffic source for affiliates. Competition with other affiliate ads is the only flaw with Bing or Microsoft AdCenter.
Araix Rand is Marketing consultant and blogger. He has years of experience on Niche Marketing, PPC advertising and WordPress.