Each day I run a report to see how I'm doing on my SERP's on Google, Yahoo and MSN. For the past three days, one of my main competitors is nowhere to be found in MSN. I did a search in msn: site:www.theirsite.com and zero results. Is it common to get banned in MSN? Is it wishful thinking that they will not return to MSN anytime soon? I'm guessing that losing all of those SERPs would have a direct impact of some sort on the other engines? I wonder what they did? Better them than me (knock on wood).
I've had sites drop out of MSN completely for a short while in the past. I'd give it a month to see if the site will return. MSN is quicker than that, but I like to allow a month before I'd presume that the site could have been banned.
There is a good chance it is only temporary. MSN is still trying to figure out what sites should show and what sites shouldn't.