just throwing my own experiences in the mix:
VI Control
VI Control has multiple Ad placements for very competitive pricing, and the quality of traffic they send is very high. Even just a T1 forum post can make a few thousand in a weekend if the forum deems it worthy
Revenue-Share Deals & Resellers
Nothing but praise for companies like VSTBuzz, PluginBoutique, LootAudio and AudioPluginDeals. They handle everything on their end and have always had excellent communication.
Youtube Reviews / UGC
I haven't had too many reviews, but any time I do they often drive a lot of high quality traffic. I plan on testing quite a few UGC creators on Youtube & Tiktok this year.
Facebook/Meta Ads
This ones a mixed bag, they can absolutely pump or they can suck your wallet dry. It depends a lot on split-testing hooks, audiences, creatives and basically every other moving part.
Advertorials
These are basically educational content where you demonstrate how you use your product to make a song. I don't have much experience doing them for VI's, but I have for other industries and they work very well, they're also free. I plan on delving into these this year as well.
KVR Email Blast
Maybe I just got unlucky, maybe some technical issue or something else happened, but I paid a few hundred USD (which is 1.5x'd here) and got about 15 page visits. I'll probably try them again in the future. Most likely a banner ad instead.
Paid Articles
Similar results to KVR. I think they get buried quite quickly on the larger websites. The benefit of these is you can add "As seen on: WEBSITE" to your store for social proof.
Affiliates
I'm categorizing this as separate to Resellers & Revenue Share. By Affiliate I mean a content creator who has an established audience. I haven't had much success with them, but I've also avoided any upfront payments due to budget reasons. I think they can work very well if you're prepared to test them similarly to Facebook ads.
I'd be interested to here everyone else's experiences 😄