cryptocurrency opinion #minnow booster is a bot that helps you boost your post by upvoting it. 
You send steem dollars to minnow booster and in return, the bot will upvote your post. The weight of the upvote is usually higher than the amount you sent to minnow booster and it is determined by the voting power of minnow booster at the time you are sending the steem dollars.
Some people have complained of not breaking even when they use the bot. It is because the voting power at that particular time is lower than 45%. It would be wise to check the voting power of minnow booster before you send money to it.
Minnow booster is very helpful because as a newbie, the sight of those cents could be appalling especially when you earned double digits in your previous posts. Your post gets more visibility prestige and rewards when you boast it with minnow booster.