Which form of marketing results in the most sales vs the amount of time spent on each platform? I would like to drop several forms of social media for political reasons, so it they aren't adding value business wise, that makes it easier. I'm also debating dabbling in more open alternatives. (Gab, Minds, and Bitchute.) I know several writers use YouTube and Instagram for both promotional purposes and as a second income stream.

What has worked for you?

It all depends on your fanbase for your genre. I know Romance does well on Twitter but hard sci-fi doesn't. I personally stay away from twitter, reddit, and instagram.

If you want to leanr more about marketing you are going to have to bite the bullet and read some books about it. I recommend "Help my Facebook Ads Suck!"

Thanks for the response. I'm well-versed in marketing, just curious what was currently working for folks here. I'll check out the book you recommended.

Definitely depends on your genre. I wrote in shtf and targeted the big forums with a few posts then let wordnof mouth takenit from there. My next one is very much not in that genre so I’m starting to lol around and see what similar others have done.

Most writers use AMS ads but I've never had much luck with them and they're getting more and more expensive.
I've had better experiences with Facebook ads, but you have to do them right.  Just dropping your book cover and description into an ad and hitting "submit" isn't going to get you the best results.  You need to research successful ads in your genre and tailor yours to match.  The image you use shouldn't be your cover, it should be something that catches the eye in an ad.  Your blurb should hook people in, not just recount the plot.

I got rid of FB as it generated no sales for me.  Just signed up for Alibris.

I just published so this thread is of interest to me.

I am currently running
Facebook
Twitter
Amazon

$10 bucks a day on each for 10 days.

I'll let you know the end result.