Back when I was on RoyalRoad, I basically did a ton of review swaps. It got some results, for sure, but a lot of the feedback was often petulant or outright useless, and overall I couldn't really get any sustained views and given how much time I spent on review swaps, I'd rather have spent all that time writing my book harder.
Here, my 'advertising plan' is a lot simpler: Just muck about a whole bunch on the forums, and that's been met with somewhat mixed results, albeit stemming from far, far less effort than before. I think I like this method more, in hindsight I find review swaps to actually be kind of toxic. Still, I don't spend nearly as much energy on advertising anymore since nothing will matter if my writing isn't good enough.