An excerpt from my piece over on Search Engine Land today, if you missed it there:
In August 2011, announcing changes to their matching behavior, the adCenter blog advised advertisers to be "prepared to take on additional traffic." Well, we didn't see the types of changes we were hoping for, namely, additional quality non-brand traffic. Instead, what we noticed was a dramatic increase in broad matching for our clients' own brand, or trademark, terms. This trend only continued into 2012.
By the beginning of Q2 2012, adCenter was broad matching brand terms at nearly twice the rate that Google was doing the same. The two engines had been at parity in this respect in mid-2011. This has led to much higher brand CPCs on Yahoo and Bing in two ways:
1) Competitor ads are being matched to our clients' brand terms at greater rates, driving up our CPCs for auctions that were previously far less competitive.
2) Our own brand ads are being broad matched to the brand phrases of others, as well as more competitive non-branded auctions, at greater rates.
Once again, for the full analysis and some tips on how to combat brand CPC inflation check out the original post.