We know Steemit works at the current scale. Lots of people are making good money. I'm interested to see if it can scale to millions of users. We're already seeing comment spam. There will be many desperate to make something at any cost. For people in poorer countries even a few dollars can make a big difference. I hope Steemit will go viral at some point, but we can't tell where the new users will come from. I want all to be welcome if they have something to contribute.