Where's your privacy once a set of "legitimate marketers" are allowed by Hotmail / MSN to send you spam? It's only not spam when it's explicitly requested. Gmail uses an automated, non-human, process to scan the text in an email and deliver what it believes
to be relevant adverts - seperate to your messages. If you're getting used to Hotmail's banners, then maybe they're failing at bringing you targeted content - so what will they try next?
On a side note, I was just logging in to my old Hotmail account to compare with Yahoo and Gmail - but realised it wouldn't let me, the usual problems with connecting I used to experience daily : )