i never really used to think about the importance of seo until recently. i always figured that, "hey, these are just my sites, only my friends read them, or they spread by word of mouth, etc" and never bothered doing anything with it.
however, after actually taking some time to search for some of my sites, i realized how important seo is for attracting traffic and for "branding." despite the suboptimal state of seo on this site, i must say that i have definitely gotten pretty lucky in this regard for this site [most of this has to be credited to wordpress]. on some of my other sites, however, i wasn't so lucky...
so don't make seo an afterthought or you may regret it later (just like me).