Uh . . . what? Tapastic's very system is built on both regular and casual readers. The mobile app was built for casual readers. Just because some readers aren't throwing money around doesn't mean they're any less dedicated to the series than you
(especially because some of these people just can't support with money, which is completely understandable.)
It depends on the comic. I'll read stories like A Better Place, Plastic Kings, and Monster Pop religiously. But then the ones I don't feel as dedicated to, I'll read just whenever I feel like it, ex. A Gentleman's Armchair, Lunarbaboon, etc. It has everything to do with your preferences and tastes and reading habits, and nothing to do with how much money you may or may not be willing to give to a creator (I'm sorry if I'm taking what you said the wrong way, that's just how it came across to me).
As long as my readers enjoy my comics and return for updates and I get the feeling they actually enjoy reading the stories and jokes I write, that's all I can really ask. The monetary support and ad revenue is just an awesome bonus that Tapastic offers (and not a lot of other websites can proudly talk about that).
I have a nice mix of casual readers and dedicated fans. The dedicated ones I find are the same ones that come in and comment every day (I can name off quite a few cough hyena421, amet, Saru-Hime etc etc. cough) but I also have the same readers who simply read, leave a like, and then check back again tomorrow. And then I have readers who are a mix of both - they come in and read every day, hell, some of them even support, but they don't comment much (but when they do, it's usually because they're genuinely interested or curious in what they're reading, which is a fun progression to watch as the story unfolds).
Advice? Make your readers feel like you care. Don't be one of those creators who can only seem to find the time to post and run. I see too many creators who do that and it rubs me off the wrong way something fierce. I get it, some artists are SUPER busy, but if you can't even make the time for the reason why you're so busy in the first place, then you're abandoning your roots and taking what could have basically been a miracle for granted.
Whenever you can, WHENEVER you possibly can or feel the urge to or have the time to, do different things for your readers. Host fun livestreams. Do Q&A's. Do some fun contest giveaways. If you really have time, do some guest strips or something. Just do something to let your readers know that yes, they matter, and yes, there is an actual person who is making these comics they love, and this actual person is damn grateful for every single one of you, even the ones who may not comment or support or whatever. Make them feel like they aren't just numbers. If you can't find the time, make the time. They're one of the biggest reasons you are where you are today.
It's one thing to be a creator who's part of a website; it's a whole other thing to be a creator who's part of a community.