topr8 - 8:29 am on Apr 23, 2010 (gmt 0)
different sites are different and there is a payoff both ways.
for instance with an ecommerce store what you are talking about has been common (not universal) practice for years - it's called, 'links to similar products'
in this case the point of the website is to sell stuff and such links can highlight other products on the site and increase sales.
sometimes it isn't all about rankings it's about making the most of the traffic that you get when you do get it.