I agree with a few things already having been said in the comment section. I think there is the ability for corporations to Try to use the site for advertisement but I don't think it would benefit them enough for it to be worth their while. Especially with the easy potential of whales having them bookmarked as posts to flag.
It is a very interesting point, but I think Steemit kind of works in the favor of being community - run (to some extent). Sure there are some kinks to work out, but it's pretty good for now! :)