By stating online site, am assuming you're referring to all sites which can be engaged with to earn money, and not only writing sites like answeree. If that be the case, then my financial broker which provides me with online trading services has to be number one on my list.
My financial broker is called pocketoptions. They solely provide trading services that revolves around binary options. Just like forex trading, binary options also involves monetary exchange, trading currency pairs, commodities, indices, and stocks. It is simply buying a particular stock or others mentioned above at a certain price, and selling at a later time to make profit. The amazing part of binary options is that the whole process can be achieved in under 2 minutes. You can place successful trades and complete the transactions in as little as 60 seconds. Profits made varies depending on the broker. With my broker, you can make as much as 96% profit in every trade. This brings us to my answer for this question. Thanks to the services of my broker, binary options trading is the online platform that has made me more money this year than any other site.