A couple weeks ago I found a chrome extension called Bit tube,

that works as an adblocker and mines cryptocurrencies at the same time.

It doesn't make your computer run slow or anything, and blocks all the unnecessary and annoying ads.

Basically it has a double use, so it's a win-win.  

The payment you receive depends on the amount of time you spend browsing.

You just receive a few bucks worth of Tubes that you can cash out through an exchange, so don't expect much.

  If you don't spend much time on the internet you will make like $5 a month, but if you browse a lot, you will possibly double or triple that amount.

I know it's not much, but you don't have to do anything... and you have a free ad blocker :)

  I for one received $3 bucks on the last 10 days I have been using it, browsing from 5 to 8 hours daily.

But if you are willing to let your computer on watching videos while you sleep, you will make more.  

Feel free to try it:  https://bittubeapp.com