Certainly a great idea. I won't be surprised if a lot of people are doing it already, but of course, it needs to be a concerted effort. Perhaps even reach out to people with a lot of followers and hook them on Steemit enough so they start sharing posts from here.

Of course, the most obvious way to grow Steemit would be to "recruit" popular bloggers from all over the internet to post on Steemit. They'll share their own posts, and maybe some others. Over time, their fanbase will follow. I'm not sure if they would right now, as Steemit is overly complicated.