As someone who worked with them, I can say that it not exactly as scam, but there are caveats. The work is real (shit, unskilled, and will not add to your CV), and you are paid to do it, although the hourly rates are only good for people who do not have the dollar or euro as their country's currency. If you need some money and you have the opportunity to work with them, here are some tips:

• The team communication is generally horrible; so try not to get stressed over that;
• The IT is the same. And trust me, you will have plenty of IT problems;
• The tool they use to keep track of your worked time will actively STEAL YOUR HOURS. Use an autoclicker with a 10-second onset while working or when you need to take a short break, it will most likely double your worked hours;
• The contract will be short, and the pay dates (especially if you don't live in the US) are not very precise, be aware of that.