You can earn CSGO skins, cryptocurrencies, gift cards using sites listed above. These sites are offering many ways to earn balance. You can complete surveys, download games and apps, watch videos, mine cryptocurrency to get balance on site which can be withdrawn.
Survey is a list of questions of a specific subject for particular group of people. You can answer questions in order to help advertisers and other businesses and get money in return. It's one of the most popular earning method among earning sites.
Watching advertisement videos is a fast way to earn money. Although, it's not very profitable and there is a limit of number of videos you can watch every day.
You can earn by downloading mobile apps/games. Some of the task will require you to complete certain action, i.e. complete level in game, most of them will take few minutes, but better rewarding can take few hours.
You can earn money using referral system, which most of the earning sites have. All you have to do is refer a friend with referral link/code (depends on site). After he signs in with your link, you get a percentage of his earnings.
Plenty of earning sites are offering leaderboards in which users that earned the most each month get rewarded with balance. If you are planning to spend a lot of time on earning site, pick one that has leaderboard with highest rewards.
Offerwall is a way to monetize app with tasks and surveys. For advertisers it's a great way to promote a product. Offerwall is offering surveys and other tasks like installing an application. It helps app creator to monetize it and user to receive bonuses without needing to spend money. On earning site, offerwalls is offering us possibility to earn money by completing various tasks.
Unfortunately, not much. Depending on time you spent and available tasks up to $10/day. We don't recommend doing these tasks for a long run, but it's fine if you don't want spend money on skins and have much free time.
Important things to remember