I have been reading a fair bit about search engines in the last week or two and there are two key points that I have noticed.
1. Search engines are not real keen on dynamic pages and neither are reciprocal linkers. With a new site the bots do not deep crawl your site at first and it may take many months for this to occur.
2. Since only 13% of the hits to most web pages come from searches it is far more important to get you url "out there" in other ways such as finding community sites where you can list you url.
The whole focus of my website is as a web directory and many of the so called "quality" sites won't give me a reciprocal link because of their link being a database reference. Ad I add someones link to my directory I always send them an email or through their contact form on their site to let them know I have added their link. Many of them return the favour but some won't I don't let this faze me at all.