A recent article* recommended three techniques: pay-per-click (PPC), linking and SEO (Search Engine Optimization).
Pay-per-click refers to ads with Google and similar companies. Each time someone clicks on your ad, you pay a fee to Google. But comics don't need this: they have Project Wonderful. Project Wonderful is online advertising built by a comics guy (Ryan North) for comics people. It's also much cheaper than Google -- about 10% to 40% the price according to reports I've read.
The main time PPC ads are useful to comics is are sites you want to advertise on, but which only host PPC. If you do a web comic about Cairn Terriers, it would be logical to advertise on the Cairn Terrier Fancier sites, and Project Wonderful probably hasn't penetrated to them. The bulk of ad traffic will still come from smartly placed Project Wonderful ads, but a Google ad for Cairn lovers seems like a good bet. (Indeed, one of my comics benefits from Russian Blue Cat Fancier traffic.)
The next suggestion in the article is linking. Linking is great, but must be done right. You want to link to sites that are similar to your own, like to other comics. Linking a comic to a plumbing supply site hurts you. Link swaps are OK, but unreturned links pointing at you are better. Links from major sites on your topic are best of all. (A Page Rank 6+ site linking to you will cause Google to index your site within 24 hours.)
The most truthful links are those that happen naturally, Google figures. Consequently, you have to barter: Joe may link to you, and you might not link to him but instead, plug him on your blog. That's a work-around. I'm not crazy about it, but it's common.
Better yet is to earn links from sites that come to respect you for not playing games. There are review and news sites that will link to you as part of their job, so if you can provide them with content, you'll get a mention. I can think of sites that get half their readers from one great link. Linking is power. Use it wisely.
Remember, a lot of people try to game Google's formulas. But a tweak here and a tweak there and the formula defeats all their efforts. Work with Google, not against it.
The article's third recommendation is SEO, or search engine optimization. This is important for merchant sites, but much less so for comics. After all, what tag words are you going to sew throughout your site to make your comic come up instead of someone else's? The only ways to distinguish comics in SEO is when the comic is narrowly focused, like my Cairn Terrier example, and in those case, your tags are obvious. Make sure it says "The Webcomic About Cairn Terriers" on your home page and Google will find you. If you do carry merchandise, it is the comic that will drive sales anyway. Few are going to bypass your comic to buy your t-shirt.
Remember that Google can't read rasterized text, meaning lettering in comics that's been converted from reading as fonts to reading as images. Most of us can't rely on our comic's words to inform Google. Therefore, we use care to mention these words multiple times in our "About" section and wherever else it's appropriate.
Google also wants to know what words are directly above your link. If someone links to you it will be much better if they do this:
Great comic about Cairn Terriers!
than if they just put the link. Google gives great weight to what the site owner calls the link.
Your main SEO planning will happen when you launch your comic online. Make sure any special tags, the name of the comic, links to similar sites (dealing with comics in some way), your name and your slogan are well-featured, but not so much they annoy readers. Install Google Analytics on every page.
Be patient and don't lose hope if Google if slow to report you. Work on your comic and network. After several months, my comics are all over the page for anyone seeking them. Fifteen of the top sixteen results for "Li'l Nyet" referred to my work. Add the word "comic" to the search and it does even better. Even "humor comic nyet" brings it in as the top result. My other comic, Scratchin Post, competes with a site with a similar name. For "Scratchin Post," my comic is the second result. If I add the word "comic" it is all the results for as far as I looked. These comics have only been on line since January 29 for Scratchin Post, and about six week later for Nyet. Scratchin Post already has a Page Rank 4.
Places you can plug yourself: you can place your comic on hosting spaces like ComicSpace, you can request to be added to link sites like Belfry, you can join a collective and mention your work on the collective site, you can introduce yourself and your work on comic forums, you can have a separate blog and refer to your work and have banners to it, you can comment on blogs and include an annotated link with your signature (no empty comments just to plug your strip, please -- make them meaningful) and when you are confident in your work quality you can write to webcomic blogs (there is a list at Psychedelic Treehouse) and share news about your comic or submit it for review.
The Google results for "webcomics" are interesting. Web Comic List and Web Comic Nation dominate. I didn't expect to see a single actual webcomic title -- but there was Sylvan Migdal's Stinking Hellibore, a comic which averages about 120 visitors/day. How could this be? Migdal owns webcomics.org. Heh.
Webcomics are lucky. We don't have to be distracted by the hype and noise and grandiose offers for expensive SEO consulting. Be glad for that. An honest day's work, some talent and some inspiration can still give us less than we hope but more than we need to keep at it.
*The article that partly inspired this one is called How Do I Get Traffic to my Web Site? by Vicki Scanlon.