I mostly use other websites as mirrors, all of which have already been mentioned so far, smackjeeves, comicfury, theduck (formally drunk duck) and dA. I am not very active in their communities outside of comments left on my updates so I can't say much in that aspect of it.
I will note that my comics are page by page, not really scrolling, so those sites are actually formatted to fit my style of comic and read better, unlike here, yet still I get much better feedback and larger reader base than I do at any of the other hosts.
Another one (for if your comic is scrolling) is the LINE Webtoon site.
To be more specific about things, as others have said smackjeeves is pretty big with BL titles and readers. To the point where I have seen a good amount of creators there put their comics under "BL" tags even though the comics don't have BL or intend to have BL. Just so that they can actually ATTEMPT to get views and compete (and the tactic actually works) Sprite comics, Pokemon comics (usually Nuzzlock challenges) seems to be the majority of other non -BL series I run into there. Regardless, I still get a few readers on that site, just not as much as I do here. I also don't like the page customization, mostly because I an't got time for that bullshit and they give you the worst default selection to choose from, half of which have broken images or formatting that no longer works.
comicfury again has the custom image issue, but at least they're not as many that are broken (this could have changed, been a while since I bothered to scroll through those really...) I get a few readers there, not as much as I do on smackjeeves BUT it's the place where I seem to get the most surprise reviews (they'll just leave a comment on a page posting a link to a written or video review) and other misc offers based off my comics. (comic dub, magazine anthologies, renplay games)
theduck has done the least for me out of all the sites. The website feels dead most of the time to the point where I don't even want to spend anymore time on it than I have to adding a new page. It's also the site that has the least interactive community for me. (Personally, others may have other experiences)
dA... not formatted for comics at all so you have to do some formatting in the comment section of every page every time you update to give readers the convenience of actually being able to read through it, some people like reading there, I also notice that the most juvenal or ranty fans that cause trouble seem to come from dA... (not everyone there is like that of course) Uploading pages there is pretty much promotional at this point, and a rather weak promotional format at that.
LINE Webtoon... I really wish it was better at helping me interact with readers. People keep posting comments or questions on episodes but the site doesn't give me notifications for those. So unless I go back and check each page manually on my own I miss a bunch of that kind of thing. It's also a very competitive site with the ranking system, and the community can tend to get very impersonal.