Download the Opera webbrowser and keep it running in the background. 
You'll make like 2-3 dollar a day = 60-90 dollar a month.
Not much maybe, but a little extra csh is always welcome.

Go to 

http://www.surfjunky.com/?r=sweden

and sign up. Open the ads in Opera, Then You'll be able to surf as usual with Firefox or IExplorer.

That's it, the money is yours.