If you like a lot of banner ads and just plain ol ads period, then go for it. Also, if you looking for better page rankings and so forth, then free hosting isn't better, it's harder to get ranked.
Free hosting is good if you run something what is not very important for you (some games, free stuff, testing pages, etc.) but if you like good and profitable site then don't use free hosting.
Free hosting is almost never free - at least in the form in which it exists on the internet today. I have yet to find a free host that is a real charity. As strange as it might sound, you should be wary of free hosts that seem to be completely free (charity-like). A host must have funding. Ask them how they cover or plan to cover their costs. Is there a foundation behind that host? It's highly unlikely, but who knows?
Well i think its not a good idea to go for free hosting service not because of ads only but also the poor performance of the servers because of the over crowding. I am using "DrupalValueHosting.com" for months and I am pleased with their services. I think they are a great company, as they are offering quality services with nominal hosting charges.