You could setup some click/phishing sites where you have smileys, screen savers, wallpaper you are giving away for free however when people download this they are also installing adware that you get paid on.. You inform them of this in the 30 page EULA they click to agree on before install.
Then you do some google search ranking and check out a few other search sites as well and drive people to these bullshit sites.
This is not very legitimate though and you will have to try and sleep at night knowing you are part of the scum that is driving the billion dollar losses to business due to adware spyware virus issues.
You could also become a computer programmer, or database administrator these guys can usually work from home though many of these positions are being outsourced.