I agree, but after the run of google/corrie ads have dried up would you still have an asset worth £15M+?
Put simply, a company could look at this a virtually 'free' advertising, with the potential to make a profit on the investment. Add that to the 'status symbol' nature of buying a club.... And who knows, the whole thing might just be a little bit fun too!
Heck, I'd say it trumps a £15m traditional advertising campaign on a number of levels...