Motivation is probably just as important as actually drawing when it comes to anything else associated with webcomics or self publishing. You have to stay motivated on goals if you want to continue to actually want to be able to get any work done- and your goals may be different from others.
That doesn't mean that, simply doing it for a hobby doesn't have anything to do with goals, maybe you just want to tell a story or maybe you want to get better at drawing or story telling. Those goals are associated with getting your work done so it's fairly important to keep such things in mind while continuing your projects.
I have actually been struggling recently with motivation issues, sometimes I feel like I am getting no where fast or that no one actually is paying attention or bothering with the release of my comics. As far as I am concerned, if I can get one person really interested, I consider myself a success. I much rather that than anything else.
Depending on what you want to accomplish, sometimes people use fame as a motivator, this is perfectly okay, I am not going to lecture people about what they can or can't do. But I find a lot of the time, people tend to use the same old tropes and cliches when they try to make something popular compared to everything else and it gets even more boring than stuff that is already out there. So if you're going for fame maybe try to use it to your advantage to make something fresher and not the same old crap people use all the time, like keeping it PG or whatever but still trying to showcase lots of sexual innuendos and what not. Nobody is holding you back so why bother conforming to it? Because of a larger audience? Trust me, online it's not an issue.
You aren't going to make a lot of money unfortunately by making comics, at least not right way even if you have a lot of merchandise it will still take forever to sell anything. For publicity, you can try to start kickstarters and what not that award them or even merchandise draws or something, which is good if you can afford it. If not it will just drag you down even more if you find you're spending so much time on merchandise that people aren't going to bother to buy.
To me, for my motivation, it's going to sound corny but I just want to be remembered, and want to continue writing so maybe in the future somehow somebody will notice what I have written. H.P. Lovecraft for instance didn't become really popular until years after his death... I kind of hope that isn't the case for me, but popularity isn't the same as being remembered. I'd prefer people remember the characters and the stories than me myself as a writer. But I'm sure a lot of you are thinking “You're full of shit!!” and maybe you're right. But I will still continue on as long as I can because I have this motivation to keep moving forward. This drive, so reach down inside yourself and find out what really matters to you when it comes to whatever it is you're doing- and what you want more than anything else, then picture failing. If failure isn't an option then don't make it one, if you keep failing find out what you did wrong and keep moving forward, above all else continue because as the old saying goes.. uggh.. If you quit after failing then you do succeed at being a failure, but if you continue on and on regardless and never quit you will eventually see success. (Hopefully).