I joined Smiley 360 about 2 years ago and have been quite happy with it! I have received numerous samples from the site and appreciate the straight-forward tasks. Like all other free sample sites, Smiley 360 has you fill out personal information so they have your demographic for their freebies. If you fit their demographic, you may have a survey on your homepage for a certain product.
I like Smiley because it doesn't tell you the brand name, it will just say a survey about a type of "gummy" or "baking soda." It then will ask you questions and if you would be alright doing certain things if you were selected. I've said no a few times to doing a campaign, simply because I only participate in campaigns of things I am genuinely curious about, not just what I can get for free. For example, the survey was on dog food and I was taking the survey and it asked if I would be willing to get a big 30 pound bag of dog food and switch it over to try. If the food was a supplement, I would've been fine with trying it, but I wasn't willing to completely replace my dog's food given the fact she is old and needs the vitamins in nutrients that her nice dog food has.
Anyways, if you fill out the survey and you qualify, you can go to your homepage and the brand of the product will be revealed. (Note: sometimes it takes a day or so to inform you that you qualify, but 90% of mine have told me immediately.) When you see the survey to join the "mission" for testing and reviewing the item, click on it and hit "accept".
They will then send you your sample in the mail and you will have designated activities to do in order to unlock the badge (you will get penalized if you do not complete the required tasks).
Also, it is important to note that you need a Twitter account to complete many of the missions, as tweeting about your product is often a "required sharing tool." I made a Twitter specifically for my freebies, so it's been nice to have my own account to voice my opinions without annoying my friends.
I've gotten a lot of great things from Smiley (much more than any other site). You can see some of my reviews from things I have gotten (which ask you to write a blog as part of the mission) on the Reviews tab. :)
*Note, my mom loves this site and she thinks it is easy to do. She has gotten a LOT of great things (more than me since she is a mother). She's gotten 2 Sleep Number Pillows for completing missions which involved her going to the Sleep Number Store and giving them feedback on the products. She also loves trying different supplements, so she has been able to get a try a lot of supplements on Smiley too. This site is easy enough for her to figure out, and she has loved this site. Would 100% recommend this site!
Here is a link to a video where I discuss Smiley 360 and show you what the site looks like: https://www.youtube.com/watch?v=gn3ZTFDsWgI