In the world of steemit getting as many eyeballs on your content is the quickest way to grow your circle and or community. This can be a tricky process it can either require extreme luck, generosity of others, or a considerable fiat investment into the platform. Another way when done correctly is the use of Resteem bots.
I personally have no issue with the use of resteem bots to help your content get a leg up, but I am here to warn you 95% are sheer trash and will net you nothing in terms of viewership. Take this one for example 
Going through the Follower list quickly reveals that this resteemer is just resteeming to a bunch of inactive dummy accounts. So essentially you have just paid to broadcast to a bunch of bots that will neither interact or follow
My advise when choosing a bot to resteem your post, go through that bots account and see who actually follows it. You will quickly turn around and run.