Good organic google listings

Hi,

I'm curious to know why one of the mini-sites on my domain is showing good search engine listings, when other mini-sites do not?

My setup is for a reviews site at verdicts.co.uk - basically, each subject area has it's own minisite with its own look and feel, and optional additional features. Each mini site is located after the domain extention, so for example, the womens interest site, and a couple of others, are located at:

verdicts.co.uk/womens_interest/
verdicts.co.uk/computer_games/
verdicts.co.uk/lifestyle/

The new "lifestyle" site i've put live recently, gets page 1 listings for many search terms, even on pages which lack content. this mini site has over 50,000 pages on it, most of which are pretty empty at the moment whilst I populate the site with reviewable places/services. Newly added places/services seem to do consistently well and appear on page 1 within about a week of adding them, particularly if they have a review.

Obviously content is king and all of that, but why do the other mini-sites not have the same luck? The gaming site does OK but not amazing but has the most content. This newer one has little content, tons of pages, but seems to do incredibly well? Is it a case of google liking reviews on services, moreso than products?

Cheers

Mat