I believe that bid-bots are good bots which you
Can use to make a post become more popular
Bid-bots can make you get alot of upvotes on your post and the more upvotes you received
The more your chances of making your posts to
Become visible

Bidbots are also good as for promoting a new
Products and services,some people have used
Bid-bots to get their contents promoted on steemit and it worked for some people while 
Some other people claimed it did not work for them but whichever way you use them i must
Say bidbots are very useful though some spammers use it to spam on steemit

But the most important thing is that you should
Use the bidbots for a quality posts because when
You do that it will enable you to be able to get effective results from the bots which could lead to alot of upvotes on your contents and also more money