Let me start by saying that I have a couple of sections dedicated to earning extra money, but this is just a post to get some skeptics going!
The casual computer user can earn $25 a month in Amazon Gift Cards and $15-$25 in cash just by doing some surveys and other free tasks.
Swagbucks gives you points/bucks for searching, doing surveys and completing tasks like signing up for free offers. You can also earn 10 Swagbucks for every coupon you print and redeem through their site. Without referrals, I have no problem earning enough Swagbucks to get $10-$15 worth of Amazon Gift Cards every month. If you have any questions about how Swagbucks works, ask me!
MyView is a survey only site that gives you a certain number of points for completing a survey. They send survey notifications (and nothing else) to your email inbox and you can take them or leave them at your leisure. The best reward on this site is the $15 Amazon card which takes about a month or so to get to.
Don't want Amazon Gift Cards? Looking for cold hard cash?
Then try InboxDollars, which pays you via a check (once you reach $30) for completing surveys and reading paid emails. You should have no problem earning about $10-$20 per month from this site. You get a $5 bonus for signing up too!
Just these three sites can earn you $40-$50 per month in extra money! You have to be a little patient, because at the start, it will feel like you are spending your time for nothing. However, when you start to cash out for all of your rewards and checks, it will all be worth it!
For a few more incentive sites and more details on the ones mentioned, check out my page dedicated to earning side money and gift cards HERE.