Website design and search engine optimization

[GateKeeper]

Are there any "SEO" search engine optimization experts reading? I want to confirm before making a definitive statement to this effect, but the classifieds website for this forum offers a premium service which lists ads in random format on the home page and other pages on the site. What I'm finding is that these ads are "feeding" the search engines with the resort information and boosting the ranking on certain keywords with that resort name in it. For example, there is an ad on the website for El Cid La Ceiba Beach. It is a premium listing, so it shows up on the home page and others throughout the site on a random basis. Interstingly enough, this ad is now listed on MSN search under El Cid La Ceiba Beach Timeshare in the #2 spot. The interesting thing is that the link is to the home page, not the ad, which would mean that the search engines are crawling the home page and picking up this information.
I played around with the terms a little more and found the same thing is true for Sell El Cid La Ceiba Timeshare, Buy El Cid La Ceiba Timeshare, and Rent El Cid La Ceiba Timeshare, except these are all in the #1 spot.
I tried a couple of others resorts as well with varying combinations of keywords, buy, rent, and sell ... timeshare for Belair Beach Club, Royal Reef Resort, and Panama City Resort and Club, all of which are premium ads, and the results were just as compelling. Before I make any bold statements about the benefit of a premium listing, and the added exposure they might receive, I want to confirm this to be the case.
Any input would be appreciated.
Sam White