FYI, the "number of posts" is the sum of blog posts + comments, thus, the other "posts" were the comments.

I was sent 0.001 SBD by this user, which led me to this blog post (the note on the transaction was "Welcome to Steem @libertyteeth, check my blogs for more ways to earn Steem & SBD :)"). Since it's not following anyone else, it must have obtained its followers by sending money to them. I'm not sure what the "click-through" rate is here, but if 1 in 10 do so, then it would have cost 176 * 10 * 0.001 STEEM = $1.76 -- which sounds like money well spent!

I've purchased some business cards to hand out and leave on grocery store bulletin boards, and store counters (bought some clear trays as well), which is around a $50 investment so far; I gave details here: https://steemit.com/steemit/@libertyteeth/business-cards-for-steemit-to-increase-participation

I think that this account's method of gaining subscribers has some merit. I like mine because it brings more people to Steemit, rather than just adding existing users to my followers -- but, it seems more expensive as well.

Enjoy!