MSN now allows advertisers to have the exclusive rights to be the only advertiser on their trademarks (not use of the name in the ad, but only having 1 ad, direct from the trademark holder on the page). This makes absolutely no sense - Lawsuits against Google have proven that the search engine has no liability for competitors (or affiliates) from advertising on a keyword that is a trademark. Also, MSN is leaving quite a bit of money on the table. If every major trademark holder signed up for keyword exclusivity, then MSN would be missing out on a LOT of additional revenue. Why is Microsoft screwing themselves and affiliates/competitors of trademark holders? I guess that MSN's massive income stream from adCenter justifies this... Oh, wait... I bet that MSN was making more from search ads when they were pulling from Yahoo then now.
Try advertising on the term Blockbuster - you'll see your keywords/ads rejected for using exclusive terms, even if your ad doesn't use the Blockbuster trademark.
A company I worked for had to in response to a competitor getting exlusive rights to their brand and then bidding up our brand term.
I think this is not wise thing from the gaints. soon it would be hard to find a keyword if all of them have been trademarked. HAHAHA LOL