All the videos from the top right advert seems to be from youtube; so it is likely that AdSense is involved.
Those that require to install things for 'free' are likely not worth it as some might contain some malware. Those that require credit card information are risky too, and some of them might require manual opting out else their system might automatically promote you to a 'premier' user and take money out of your credit card account. Also, installing and uninstalling a lot of apps. may have negative effects on your PC's performance later. If someone does this, he is simply sacrificing the good state of his PC for a few tokens. The same thing applies to mobile phones. Take into consideration that there must be some way for those that provide those offers to make some profit, else they would not have provided such services.
As for the play a game and reach a certain level or points offers, for many of what seemed simple browser games, the levels or points required seemed impossible to attain. For the multi-player online games (MMORPG), the levels required seemed attainable after a few days to a few weeks of playing, but I have completed one of those requirements for a game last year and did not receive any tokens. Also, these games are likely to be addictive or traps. So, briefly, you are more likely to waste a lot of time and effort on these, and also might fall in their trap. If you want tokens, better buy them straight from the 'BUY TOKENS' option found on the right of the page of the browser version of the game.