Yes, I found it very hard to find someone who allows NSFW traffic. I run one popunder and one of these "hey chat with me" windows in the top right per page, and I excluded the fishy stuff like Entry/Exit-messages, android downloads and such, I figured that would cause more problems than it's worth. Normally my earnings per 1k views is between 20 and 30%, which is not a lot but keep in mind all that is 18+ traffic which hardly converts to anything. Occasionally I have days where I am suddenly at over a Euro per 1k, so it fluctuates a lot. All around I am looking at around 10-30k views daily on my main and 50-100k(on weekends mostly) combined, some blogs have daily recurring visitors and others only spark periodical interest every now and then. I think running several is the only option, especially considering that tumblr is known to sometimes ban people's blogs out of the blue without anything going wrong (they allow ads) which could really harm you if you focussed on one single blog. Also running several in different niches means that it doesn't get boring. In total I spend about an hour every two weeks per blog I run to fill the queue and every now and then I will manually reblog stuff I find fitting throughout the month, so I'd say very little actual work. Expanding past 40 is so far not planned because I would quickly run out of spare time. What I did though was set up a small network of ifttt.com automated tumblrs under different accounts that reblog my blogs automatically and gain some followers, but those have yet to gather serious interest. They gain some followers, but I think the biggest one is at 500 so there is not much coming from those. Still, I think I will expand that as soon as I find some time, great that the holidays are waving at me from the distance :) So to summarize: Divide the number of your daily visits by 3.5 and you have a good impression of how much you earn. Unless you have something that is at at least 100k (~30€ a day = 900€ a month) it would probably not be worth it considering how much work it would be to build up such a blog. Compare that to 3 or 4 with 30k followers (which is a lot more likely and easy to achieve) that would generate the same, or again 20 with about 5k followers and keep i mind there is always a chance your blog is gone the next day even if you did nothing wrong and it is much better to run several smallish ones.