I was thinking about starting an outsource hosting provider service.. what you think of this idea? i make alliances with large companies and they will resell my hosting services.. with their own brand

If you have the rigth stuff, it will work. It needs to be a fully branded servoce (not co-branded bull and not affiliate crap where allied companies end up selling/advertising your business for free) - you just stay behind and manage operations while service providers brand and sell their own packages/services.

I have seen a company which does this already and is a provider for sbc, at&t, etc., I suppose they are associated with webhosting.com and tophosts? But one could do this on a small scale as there are a lot of other small/medium businesses who can provide services for their client base.