So far, I've tried to be a little scientific in my approach to studying Steem Promotion Bots. I've tested the options carefully, collecting data points here and there.
But this approach is fundamentally flawed in one respect: I only post three times a week.
That means I only collect three data points per week, which is not enough to make a meaningful conclusion in this ever-changing crypto world.
I'm saying this because a few commenters have specifically asked me to keep them updated on my experience, because they want to know if using promotion bots is worth the effort, and my approach has this blind spot that needs to be acknowledged before I can make any claims.
With that out of the way, I believe I have learned a few things over the course of the past week.
For monday's post (Muppets: Infinity War, Part 3, in case you missed it). I decided to space out my use of promotion services.
As usual, I submitted the post to MinnowsBooster right away, but I waited ten minutes before submitting the same post to Smartmarket/Smartsteem. This produced good results, as I finally managed to get Smartsteem to use the entire SBD I sent them. Meaning I did not get a large refund, but the result was still welcome.
This, however, did not work for my post on Wednesday (Netflixing: Agents of S.H.I.E.L.D., Season 4, in case you missed it), in which I got more than 75% of my contribution refunded from Smartsteem.
It would appear that Smartmarket operates according to a very particular time schedule, and it can be difficult to get the timing just right. They seem to have a very large audience, so being able to use 100% of your contribution could really make a difference. But, alas, it is not so easy to hit that sweet spot.
For wednesday's post, I decided to splurge and give 2 SBD each to Minnowsbooster and Smartmarket.
Unfortunately, as stated above, Smartmarket used less than 25% of my SBD, and I got a 75% refund. Meaning that instead of spending 4 SBD, I only spent 2.5.
For most of my past experiments, my final cost came to about 1.5 SBD, so Wednesday's post ultimately only had 1 more SBD spent than usual.
And the results are...inconclusive. The post made about $12 overall, which is definitely on the higher end of what I usually get, but monday's post, on which I spent only 2 SBD, netted me an $11 total.
So for the additional .5 SBD, I only got 1 U.S. dollar.
On the surface, it would appear that giving each bot 2 SBD instead of 1 SBD is not more profitable. But then, I've only tried it once. And with just one data point, I can't conclusively say that this is the case.
Astute reader 
But, at the moment, the TipU service is still small, and can only vote a few times before it needs to begin a cooldown period. From what I hear, it's trying to expand to the point where it can handle a much larger user base (and based on its popularity, it may well reach that point). Still, for now it is even harder to time than Smartmarket, though I'm still open to using it.
However, TipU can also be used as an investing service, where you send a certain amount of Steem or SBD to TipU and get a percentage of TipU's curation rewards back. I haven't tried this, but it seems like you can invest this way at any time, even during the cooldown period.
The way I understand it (and I could be wrong) is that if you want to get a TipU upvote, you send the SBD (or Steem) to TipU with the URL of your post in the "Memo" line. Whereas if you want to invest, you send the currency with the word "invest" in the memo line. Investments can apparently be done whenever, whereas getting upvotes can only be done when TipU is active (and you will get refunded if you try to get an upvote during the cooldown period).
Keeping in mind that I have not personally used TipU yet (though
Like I said, I only post three times a week, and this doesn't give me a lot of opportunities to branch out and experiment.
Unfortunately, posting more frequently is not an option, as I simply do not have the time, and I am more interested in producing quality rather than quantity.
But, though I may not have any answers right now, I have gathered enough data to narrow down my questions to the ones that are most helpful:
These are the results of my current dabbling. Thank you.
[Update: By sheer luck, the 
