well if you want a second opinion i can give you one as being a webcomic artist myself.
I draw a comic which is hosted on the free web comic site DrunkDuck (it's ten times more simpler than keenspace. (comicgenisus or whatever it's renamed now))
In my professional opinion a webcomic is always first about the writing. you can have the most wonderful drawing in the entire world but if you don't have the writing skill to back it up then your comic will full downhill. Art dosn't have to be very good, look at adventurers, that was a highly successful comic and the art is crap! my own comic starts off with crappy style on purpose because i was A) lazy,

busy with three other comics C) couldn't be bothered to waste more time on a project that I'd probably give up on in a month. but my comic hit it right off in the drunk duck community because even though the art was crap and simple, the idea was original and the jokes were funny. (well they say they are, I'm not personally convinced)
I have now been drawing my webcomic for two years even though i thought it wouldn't even last an month. i have two thousand readers per day (probably more all together) , I have 193 comics and i must say i have no intension of giving it up ever. because like Lar says. making comics is allot of fun. it is probably one of the most enjoyable hobbies you can have. I enjoy making my comics and thousands of people enjoy reading them.
sure don't expect to be a hit off on the first day. it can takes months even years to get noticed, but once you do you do hit high. don't start think of merchandising until you actually have a fan base. it's a waste of time otherwise.
and when you start a webcomic, decide at the beginning whether you want it to be a story or a comic, and then bae you layout around it. it'll pay off later if you want to publish it. i didn't make these decitions and now i have to redraw the first hundred and so strips if i ever want my work published XD if i had known I'd still be drawing NPC two years ago i so would have started off better. :3