When I first started Swagbucks, I was wowed. I was earning about 400 swagbucks (around $4) a day. I got so many gift cards. I've made a few hundred dollars on the site. After the first few months though, it seems like things dry up. The people who give out surveys gather information about you and know who you are, regardless of what you answer, so you get disqualified from a lot of surveys because they don't want repeat survey takers.
Most of the stuff in Discover is a scam. Like for instance, if you go to Peanut Labs and look at most of their offers. You can find things like "earn 140 swagbucks and get a free Starbucks card if you fill out the questions." You will never earn that Starbucks gift card OR the points.The website it links you to will ask you question after question and then inevitably take you to a point where you can't proceed. If you've ever seen one of those "congratulations, you've won!" ads and clicked on them, this is along the same line. You can complain to Swagbucks and more than likely they'll give you the swagbucks, but not the gift card.
Swagbucks is a mixed bag. You can make a nice amount of spending money, but it takes time, and you will have to fight them for swagbucks you earned that you didn't receive.