Liquiteq has some excellent points, but that is all in the highend of
SEO or web positioning as a whole (positioning - broader topic). Those tactics are applied for competitive industries where alot of knowlegdeable peeps are competing for high paying phrases and keywords, as in stuff that makes it all worth it.
Also some nice points about surrounding content and pagetitle of the linking page. Altho I'd still prefer static URLs linking me, G
are getting alot better of picking up dynamic ones so I predict it won't matter much in the future. But for now I'd stick with static as well.
Deep linking can be both a powerful tactic and a dangerous one, as you face the posibility of putting too much weight on one section of your site, causing it to fall out of balance. If you decide to work your sites deeplinking, I would suggest balancing your site in the way of keeping your main sections equally weighted. I've had success applying those tactics in the past