Some sites pay you to complete surveys online. The amount of money will differ, and so will your eligibility for polls, as the website will decide which one you can take. This is based on how much information you provide them, so they can accurately sort results. With enough information and some time, you can stand to make a decent amount of money.
While these sites are hard to find now, they are not non-existent. The most common form of payment is to pay $0.05 for every ad you click on and spend 30 seconds on the linked page, $1.00 for every active person you refer, and $0.01 for every ad they click on after sign up. In time, you could stand to earn from $30 upwards a month, so these programs should be used as secondary streams of income.
I haven't earned much money from this form of money making, but the potential is definitely there. You basically get paid per 1000 downloads, and the amount depends on which country the file was downloaded in. The amount of money ranges from $30 in the US to $5 in Russia, but the amount is different depending on the website. You can also make money from referring friends, as long as they upload files and remain active.