I just started posting on Steemit a few days ago and my first several posts got a few upvotes at best. The last two got 25-50 each within a few minutes just like your post described. Looking into this I agree it's designed to get upvote money by getting in early but I also wonder if it's keyword indexed or somehow focused on certain titles or categories because as I said some post it happens and some it does not. Hoping my content creates that level of interest someday but for now, thanks for this post to help me understand what's going on.