resteembots are bit of a hit or miss. But on the long run using about 3-4 bots on each post has had positive returns. In fact considering engagement they are more cost effective than voting bots. Sometimes I have gotten about 8 new followers after going to sleep sending SBD to a resteembot. Sometimes I barely get any followers or comments after a resteem.

If you are making good content and use a bunch of resteembot you are bound to get decent results based on my experience.