INAL and I don't want to piss on a good idea, but the first thing that came to my mind is that company logos are trademarked and that you might be opening an unexpected ball of hurt for yourself.
While a company's logo may be under trademark or simply copyright protection, you still have a legal "Fair Use" right to use the logo for the purpose of identifying or describing the company.
Most often, this is what logos are used for on a site. For example, "As Seen On... TC, CNN, blah blah blah". They obviously cannot be used to mislead someone into thinking the company is tied to or endorses your site.
Here's an article about it: http://smallbusiness.chron.com/fair-use-logos-2152.html
Funny thing about trademarks, I can go take a photograph of the Pepsi logo and then if they use it without permission I can sue them!