Footer Links on Big Sites

Diminishing value of thousands of links from a single site

[P0pcornB0y]

If a good, mature, high-traffic classified ad site has tens of thousands of indexed pages and a deal is worked to place a link in the main footer and you end up with 10's of thousands of links...

Are there any issues with having that many links come from a single domain? And... how is that compared to 100 links from a multitude of sites? Does that make sense? In other words... 100 good links from many domains compared to 10's of thousands of links from the respected domain mentioned above.

What would you do and why?

[idolw]

sitewide links - should not hurt but won't really help much unless anchor text varies.