A buddy of mine shared some correspondence he has had with MSN in regards to a site of his that has been apparently penalized in MSN SERPs. Not banned, mind you, just penalized.
Over the course of several months, he has been in a discussion with MSN support reps about why his site may be penalized. Of course, for the longest time, it was mostly autogenerated email replies telling him to read the guidelines. My friend, however, is quite persistant (he's like a dog after a bone), and he refused to let the situation end with autogenned content.
Several human responses alluded to a possible problem with a link exchange directory that my bud has on his site. However, with a bit more persistance, he finally got this reply (he has approved my sharing this with you, btw):
As weve stated before, your site is acquiring links through posting to or exchanging links with sites unrelated to your site content in an attempt to increase your ranking. These links are considered spam and your site has been excluded from our index as results. Please contact us once you've removed these links and we will reevaluate.
The part that stands out for me is the phrase unrelated to your site content. Of course, my good buddy is attempting to clarify this statement even further, to make sure that the only thing MSN has a problem with is exchanging links that are unrelated, rather than the mere act of link exchanges in general.
I asked him if he intended to dump the recips in order to appease MSN, and he says that he won't because he gets more traffic from the sites he has exchanged links with, than he does from MSN Search. Interesting...
If he gets any further enlightening responses, I'll be sure to share them here.