Bid bots.
Trending + Hot posts got dominated by people that spent a lot of money on bid bots. No matter how good or bad their post quality, as long as they pay a lot of money to bid bots, their post will become trending.
Meanwhile, people that doesn't use bid bots won't get anywhere on steemit without help from some dolphins or whales.
RE: A Bit Curious Contest #2 100 SBD in Prizes - 7-10-18