Imagine a scenario where Google or Facebook introduce their own currency. With Facebook and YouTube having a 'reward in cryptocurrency' for upvotes, comments, sharing information.
Is that scenario possible? I don't think you actually need blockchain technology for this... (Of course I know why I prefer the decentralised technology. But what percentage of Facebook users does?)
Will steem be able to counter this?

Cryptocurrency is worth what people are willing to pay. Whether there are 1 million or one trillion coins, it's what people are willing to pay.
At this moment, that's quite a lot...