ok, today is a great day and i am in the mood to unveil some details.
these are the points to consider on which page you want your link on, not everyone will agree, though. this page should have (in competitive order, top = most important):
1. comply with google TOS
2. toolbar pr (it's not as important as it used to be, but it is still a very good indication)
3. a relevant theme
4. 10 or more outlinks to relevant pages
5. inbound links from relevant pages
while the points 1-3 and 5 are clear, point 4 looks odd: for pr distribution a page (the page which is linking to you) should only have a few outlinks as the pr is distributed among the outlinks (5 outlinks - your link gets 1/5 of the pr power, 100 links - your link gets 1/100 of the pr power). but pr is not the only factor which matters. there is a thing called Hub Score (which is not a factor in the original google algo) which is achieved by the linking page. if a page links to many relevant pages this increases its Hub Score and makes the linked pages more relevant. Think of this: an asian category page links to an asian free site, this very same asian free site at the same time is linked by many other asian category pages of other linklists. this makes the asian free site more relevant and also gives a good hub score to all linking asian category pages. the hub score says 'this page links to many valueable pages, so a page listed from that page must be good'. so the more outlinks an asian category page has to pages which also are linked from other asian category pages makes that asian category page a good resource (or hub) for asian free sites. from this point of view, it makes a link from such a page more valueable. sounds logical.
but what is the drawback from having a link on a category page with many outlinks? as mentioned above the pr is distributed among all outlinks equally, your page will not receive much pr value from that trade but much thematical power.
how should you trade? you should mix it as it comes. webmasters have different opinions, some only want reciprocal trades, some not at all, etc. so the mix happens automatically with your partners link behaviours. this way you will get some pr power trades and some thematical relevant links. now you only need good content and the surfers will love your page
