JMHO Bring the heat MSN!
What will hurt Google is when webmasters in the millions start to advertise other search engines on their sites. If only 1 in 10 use the search engine off of our sites and find better results for what they are looking for do you think it will tell that search user anything about Google's deteriorating SERP's? Now times that by however many sites each webmaster admin's. I myself never used MSN and now I use it daily. I used to use Google everyday but not anymore. Why should I when I can't even get relevant results? Nothing is more annoying than going to a site that appears to have what your searching for and it's nothing but a PPC content site. These particular sites seem to dominate google's serps in my industry. Some say Google Adsense has no bearing on where your listed in SERPS but I have a hard time believing that when these crap PPC content sites dominate the top 10 and have zero content. It's quite sick when a text link dominates because the webmaster crosslinked his couple hundred content sites!
Bring the heat MSN!