Brian,

There are some recent articles about this on The Art of Marketing You & Blogging & SEO groups. 

My thoughts:  The criteria for SEO changes all the time, many times per year, just like the most popular search terms/items do.  Links from "embedded" pages on a site are almost useless.  Many of the links agents trade with each other are from a page that is very hard for humans to find because it is so deep in the site. I got an email this morning from a UK company saying they had linked to me already.  I used the link in the email to see my linkback, but when I went to the main page of the site, and even when I used their search functions, I couldn't get back to the page my link was on.  This is an example of a "spider only" link page.  These are pretty useless.

Some SEO techs say reciprocal links/trades are discounted by the SEs.  Your goal for SEO is to have more inbound links than outbound links.  That will sometimes offset any "trades" the spiders are programmed to see.  The latest method for getting link credits is to comment on blogs.

Also, if you keep your "trades" to top level pages (first or second tier) of sites that have relevance to yours, you will have more success.  And, I always suggest that the best way to make your SEO easier is to follow the example of the NWMLS by stopping feeds to sites that are competing with you for SEO.  Most MLSs haven't studied the NWMLS action or have ignored it because their members don't know about it.  In areas where they understand what and why the NWMLS did what it did, similar actions are in progress.

I'll look at your profile to see if your URL is there, or if you send me your site I'll link to it from www.REindex.com from the towns your listings are in.  REindex (Are-ee-index) is my 8 year old project to help agents' pages get found regardless of their SEO.  We are "REindex.com, The Site Engine(sm)" because we help real estate websites get found, and we help consumers find their home site.  We have a YouTube - search for reindex.com on YT.

Lastly, instead of links in to your site, try studying the code of the sites that are the top ranks in the search terms you are trying to SEO for.  My real estate company site is CapeGroup.com and I work hard to SEO that to the top of the organic results for terms relative to my town.  What works well for one search engine may deter another so you have to experiment, hire someone, and/or buy lots of software.

There are many SEO chatrooms that techs discuss linking in.  Also, understand that many techs getting top results either have little competition for their specific SEO term, have a very large budget, have lots of time, and probably have all three.

Best wishes,

Heath Coker REindex.com, The Site Engine(sm)/CapeGroup.com Cape Cod Real Estate

Thanks for the thoughts on cross linking.  Advanced access did that with all their clients a few years ago and were punished by the search engines later.  The rules change in SEO.  What is good this year may be bad next year.