Honest review of spending $40,000+ doing this! 5/10!
The results varied MASSIVELY to the point where the final run I had spent $6500 and got literally ZERO results for 10m DMs, the very first results were not bad on some pages but on other pages they were horrible. I only had 1 page in particular that it worked somewhat well on but it also has VERY fast diminishing returns, the results start to taper off quite quickly once you have worked through a good portion of your target audience (within the first 30m DMs tbh).
All in all, 5/10, don't feel like I got my moneys worth overall and it definitely does not make ROI in many cases so you are going to need to be willing to lose money. The few cases (2-3 runs of 5M DMs) I did get ROI did go very well though, everything else at most its a small platform boost.
Thank you and I hope you enjoyed my honest review.