Yea but if they bought that much Steem it wouldn't really serve any purpose of further selling their product. People have millions of Steem, I don't see how it really helps Coca Cola to have more than ten thousand to 100,000 or so. It would primarily be used to keep themselves from being flagged because they upvote their own blog post and they would upvote other people and reward them for logo designs or contests or something.
Icould see a lot of people signing up for stuff like that. I guess.
I don't exactly see why almost any large corporation would put millions into Steem, but if they did I think the original creators still have a large portion of Steem between themselves to flag abusive stuff at least, +the community would like you say above.