Sort:  

Thanks for answering. It is because of your use of services like Booster, Minnowvotes, thebot etc. The reward system is made so people can compete who has the best post, but with these services it is like when a football team buys the victory in a match.

After the latest hardfork, people here on Steemit has decided to make people stop using those bidbots. So that is the reason.

Now how can I invest steemit?

You can buy some, but your earnings should come from how others vote on your content. Buying votes is reducing what others can make. Just because this service exists does not mean others cannot reduce your rewards. We do it to get a fairer distribution. Try talking to other users in comments to make them want to follow you. If you have something of value then you can earn. If you just post random pictures you find online with a few random words you may not be doing that.

What steevc said. Power up and start curating, connect with people, make posts with original content.