SgL: the problem with social media is that it's hit or miss, especially if your readers are very active. I mean, yeah, I do "follow" some things via social media, but that means I'm not really following, I'm just hitting things now and then among the million things that pass by my eyeballs.
If you want to actually follow something, especially if you have a lot of sites you want to follow without missing anything, you've got to use something like RSS. Or you have to just go there every day, and not rely on anything else.
And that may be generational: that "the kids" don't really get into close following except when they are so enthusiastic they do it manually. They don't mind missing things. (The great thing about web comics and serials is that you can freely miss things. You can catch up any time.)
One thing I've noticed, on my own and also talking with others who use multiple trackers to observe: that RSS is just about the most fruitful sources of regular readers. Those readers do not comment or interact as much, perhaps because some of them read via an RSS reader instead of directly on the blog.
A surprising number of direct hits, though, actually come from RSS feeds. This can be hard to see because they're invisible to some stats trackers (it's seen as server traffic or something). Plus there are things like Kindle Feeder, which is not at all visible to the trackers as far as I can tell. It aggregates your RSS feeds and sends them to your Kindle. (Not good for webcomics, though, because there is a file size limit.)
I still haven't found out how Paper.li works, but I presume that's another source for people to follow what you do.