If you look at who voted the top ones will be those with the most Steem Power. If they have many thousands then you will make more than if they just have hundreds. You need to build a following. Follow people and comment on their posts, but don't just ask them to follow back.
The system is designed so that people can't game it by creating lots of accounts. There are lots of 'bot' accounts, but they don't have enough SP to give anything with a vote.