Another latecomer to the thread.. I haven't been checking this forum lately, alas.
I guess this could sound kinda cynical, advising you to become part of the community for business reasons, but really, being part of the community is very fullfilling in a multitude of ways and it provides you with a group of people who are willing to help you in many ways be better at what your trying to do, whether or not that's putting out a better product, or if just trying to be a good DM. Get out there, post, help people with questions, help get your questions answered and that interaction will help your business in the long run.
I agree. Get out there and make your name known among the masses. People are more likely to at least look at your product if they know who you are and what you're capable of doing. Add your opinion here and there, offer to help other writers when and as you can, get involved in discussions related to the things you're writing (that last, incidentally, is a great way to slip in a reference to a current or future product). We, as writers and publishers, cannot stay up in our white towers above the rabble - we have to be down with them, to see what they want, how they think, and what they need, and try to fulfill those wants and needs.
The best way to get noticed is to do something new, or have a new spin on something. Doing "yet another class book" will get you relegated to the horde of publishers who have done the same thing to death; doing a book on fighting styles with various weapons, including feat progressions, PrCs, new items, and maybe a sample NPC or two will get you recognized as innovative.
If you go into IRC at all, it's a great way to meet and greet other folks in the industry. I'm not really good at schmoozing, to be honest, but my co-writer, Tim Willard, is great at it - he's made contacts with half a dozen other companies, forged links with them, and gotten us work with them (at this point I should note that we are a production house, not a publisher - all we do is write the books, then we ship them off to the publisher and they do everything else). But still, making alliances with other publishers is always a good thing - if nothing else, you'll have some drinking buddies at GenCon. But seriously, if you make contacts with other companies and they like your work, they might well allow you to reference their material or use if wholesale, which provides more exposure for both of you.