Getting Paid To Take Surveys?

[iBirdiee]

I have seen a lot of websites and advertisements that claim you can get paid, only for filling out some surveys for free online. I was wondering if anyone has ever done this and if it is legitimate? I am pretty convinced it is already a scam when they ask you for your cell phone number and such, but I am still curious. I'm sure since there is enough of them, someone has had to of made some money from it. Please share your experiences!