It depends on how you use them... If you use an upvote bot to increase your payout then you will loose. I spent a great deal of time when I first joined steemit using upvote bots on my post and then tracking the payouts. Overall, after you take into account the 25% curators get paid for you post as well as the gradual decline in value of your post over the 7 days you generally just about break even.
As a new user i think the upvote bots are valuable in providing some much needed visibility to your posts. In my view its a form of advertising which was borne out of the fact that the built in promote feature in steemit is terrible.
The other issue is that so many people use them no that they've become saturated with vote requests and the value of your bid has to be really high to be worth anything. I've seen people putting upwards of 40SBD into a single bid.
Its a legitimate tactic to use to promote your posts, but if you try to use it solely to boost your payouts you will loose. The math is not in your favour. In the end, like any strategy on this platform, it is an individual choice, and I rarely use upvote bots but I prefer not to use them at all anymore.
Great perspective I think lots of people have agreed that it is a great way to promote the post and I am wondering what sort of return on investment that they considered to be worth the fee as a marketing View for instance how many followers did they get how many Resteems and how do they track that information?
That's tricky I think. You can use things like steemd.com and other third party tools to track your performance but all in all you cannot definitively identify why someone decided to follow you.
I read a similar post the other day about someone's experiments with voting bots. Although they gained followers, the rate at which they gained them was no different than when they weren't using the bots which would suggest it has little effect on followers.