People here just want to earn money. Its nice to earn money by sitting in pc for 2 hr per week. And through bounty you can actually earn around .4 to 1 eth per month. it depends

There is a common rule – things that could be made by everyone, cost little. Tasks in Facebook and Twitter bounties are rather simple and convenient even for newbies, so there are a lot of participants, and it decreases the stakes. And vice versa