Yes! Indie online comics are way different from published print comics (audience age, genre, etc). Have you tried to work with publishers? If you really want to work with comics, send a submission to a real publisher. My two cents
My background and why I told you that:
I'm veteran from the comics industry, working full-time as comic artist. I had the same hard time as you when I tried online comics. After an entire year, I'm quitting online comics after I upload the my GN and an extra. The funny thing is, I had no hard time to find a real publisher for the print version of my book and they can manage to have a Diamond distribution for it. But online comics? I'll try another project someday, when I create a project... suitable for this format (and genre, and audience age, and more cartoon etc).
No regrets, the experience with online comics was great, though. The community is great.