Normally I would say quality > quantity but on this platform quantity gets extra weight because of how the algorithm sorts results (by number of sales, not by revenue).
Also it’s worth taking into account that it’s very likely you will end up making most of your money from only a small percentage of your portfolio, so therefore a larger portfolio gives you a better chance to hit the “trending” lottery and have one of your tracks shoot up in sales quickly.
In my limited experience here I’ve noticed 1) that about a third of my sales have come from one single item out of the 70+ in my portfolio, and 2) whether or not a track “trends” seems to have little to do with how good it is.
In fact when I uploaded my first batch of items, the one that I thought was lowest in terms of quality out-sold all the others. I’ve been consistently wrong with predicting which of my tracks would sell well. My highest selling item is a logo that took me 15 minutes to make, which has made me 3x the revenue of any other item in my portfolio including many that took much more time and effort.
So given all that my recommendation would be that quantity is important whether we like it or not. It would be nice to upload 1 track per month and just ride into the sunset but unfortunately it doesn’t look like it works that way, consistency is very important.
I will add that there was one month I hit 30 uploads and sure enough my sales and income skyrocketed for that month. I couldn’t sustain that pace though so I slowed down and sure enough the sales decreased. I can’t speak for anyone else of course but from my experience there has been a very direct and predictable correlation between how often I upload and how many sales I make.