That's because
SEO is still one of the 'Black Arts' and people still tightly hold on to that knowledge.
The number of relevent links in and out of your site will always be a priority task with any
SEO task. Using directory sites is a great way of ensuring your site is listed in the first page of a search, even in the early days. There are many free directorys and their
SEO has done all the hard work for you.
Links to local businesses, attractions, club sites, tourist information and local government services can also be used [to great effect]. Reciprocol links might be quite hard or impossible to obtain although worth every effort to get one. The additional bonus is that you could also use the target sites main image or logo giving you [usually] some nice interesting imagary and Kudos - people assume you are connected in some way, and your are - but not in they way they assume.
Paying for a directory listing or Google Adwords is an option but payback from these listings is, in my experience, a non-starter. I look at such payments as a capital expenditure - to get my site ranked, rather than a traffic provider or money maker - although it could do both.
Google Adsense is free and should at least be considered. Even though this is going to list your competition [on your own site!] it can have it's uses when making your information pages more relevent to bots by providing external links to similar relevent sites. Your site users may use these links to navigate away from your site and buy elsewhere - but do you ever click them when your on a site? Nope, me neither!
Hope this is continuing to be of help.