Problems:
- Any money link, inclusive autohosting sites is a risk of being banned.
- Now you can't change click thru/source link on reblogged pictures.
- Adult blogs are invisible on mobile (more than 50% of nowadays traffic) because tumblr hide them (adult search is disabled on mobile/tablet app or mobile/tablet web browsers).
- Due to it, the only way to gain followers is social network sharing (TW,FB,G+,pinterest) but be careful because only TW accept adult content. The second way that consisted in create a "white blog" (no links, no ads,...) and once a week reblog a white post of the tumblr you want to promote, is over (at least for me). As soon as some of the promoted blogs are banned tumblr mark the launcher blog as suspicious and the banning arrives soon.
Nowadays it's hard to maintain active a tumblr with ads or affiliate links more than a week (On 2013, it was easy to keep it active one or two months). Nowadays it's hard to gain more than 10 followers a day, in the early 2013, I could gain a hundred a day easy, and 200 in successful tumblrs.