There’s also the matter of whether you’re sending purely unsolicited DMs or preempting the DM with a follow-back from the target. If taking all actions into account:
High Quality slave positioned to look as a theme page > follows 300 targets per day > 3% of targets followback > 10 DMs sent > 1-2 followers received via mother account.
That’s been my general trajectory across several niches. If y’all are getting up to 5 followers per slave, what I am doing wrong? Poor targeting perhaps?
First of all, 3% FBR is extremely poor. You might consider to increase your FBR. When I said +1 to +5 followers / child account / day, I didn’t mention the number of actions. But certainly with 300 follows per day, you should be able to bring +3 to +10 FBR to @ mother account.
Then, there are a lot of other factors than play here, even within the same niche. For example, activity of the main accounts are also a major fact. In your case, it would be pretty easy to increase a FBR, so I’d suggest you to try out various strategies, and see the ones that work best 
If the targeting is bad, then you might consider to first have a look on this, because there’s no way you can deliver results without the right targeting. Also, many tend to forget, but filtering is as important as targeting.
What would be a decent FBR in your experience? And do you mind shedding some more light on what “filtering” is? As in excluding non-English users from your scraped profiles? Targeting specific keywords to avoid other theme pages as opposed to actual users?
Are we talking about the average Child accounts FBR, or Mother account FBR ? To me, 10% for the first one, and 20-30% for the second. You can do even more, but that’s a good start.
Meaning that with 300 follows, you should be able to gather +5 to +10 followers as I said earlier
That’s a very important matter, that every clients will be looking for. It brings the question : what kind of followers are you trying to send ?
I’ve seen M/S providers saying they grow accounts easy, with a very high FBR to mother account. Thing is, it looks good on IGblade, but for some awfull when you look deeper ; they don’t filter anything, and the followers received actually have no avatar, big-big following (useless), or private ones… In that case, talking about % FBR is pointless, as your FBR will be high because these accounts follow everyone. I’m sure it’s possible to get +10 to +15 followers to main / child / day with low filtering. But what’s best, quality or quantity ?
Always try to hit as much quality points as you can. Then, if you can scale this up, your clients won’t leave you
Hope it was clear
It’s an example of filter, yes.
Yes that’s super informative thank you! Are your services for sale?
You’re welcome.
I don’t have a sales thread here so can’t say 
Respectable.
I gave it a bit of thought and concluded that perhaps my low FBR could be attributed to the fact that I source most of my targets from the lists of followers of other theme pages in any given niche. There’s a strong likelihood that I may be wasting my follows on inactive profiles that had followed the source ages ago and are no longer on Instagram.
Am I better off sourcing my targets via likes off recent posts? To ensure the profiles have actually been active in the niche within the last few months or so?
Likers, Commenters, are always a great value versus “Inactive” accounts. However if you play with M/S for some months, you’ll be users-limited if you only scrape active users. And even worst, it might be spammy for the ones that don’t properly erase duplicates.
On my end, I’d rather “take them all” especially if you have a lot of child accounts in that niche.