My advice is "Don't get ahead of yourself." Arguing about marketing and webcomics is mostly a waste of time, because so few webcomics are to the point where they could do well with it. Focus on having a good webcomic first. Don't focus on having a webcomic that could some day make you money. Because it should be common sense that a crappy web comic is not ever going to make money. Except 8-bit (sorry, couldn't resist.... hate sprite comics).
Also, if you want to have a good webcomic, you should find one that you like, or that you know many people like, and use them as a model for your own comic. Do not copy their content, of course, or even their style, but the best way to learn how to do something successfully is to follow the example of those who already do it successfully. Layout, navigation, cast page setup, etc. are all things that make a webcomic great, and all things that can be modeled after sites that already have a terrific setup.
Lastly, all of this talk about webcomics that earn money has appallingly left out Girl Genius, By Phil and Kaja Foglio. What's with that? They have a regular readership of about 150,000 people, and make their living from their comic(s). Why? Good art, good story, smart business plan. They are certainly good role models for those who wish to have a successful webcomic for fun or profit.