I have seen and heard a lot of discussion about whether or not to use footer/sidebar links to other properties you may own. Some say Google discourages footer or sidebar links however I see this practice often with mega-sites like Amazon, Ebay, and many news outlets.
So my question is not so much what does Google say, but what is actually working and is the fear of footer links overblown?
I have 5 sites, all in the same niche, all catering to a different need. 4 are info sites and one is a social network. Should I do a footer link to mygreatwebsite.com/myothergreatwebsites/ or should I just do footer links to each website like the big boys? What works better? 10,000 footer links with little page rank pointing at my 5 sites or 1 page with 10,000 links pointing at it with 5 different links to my other websites? Does anyone have any experience with results concerning this?
If I were writing an algorithmic smell test, I'd look at a number of potentially questionable or shady factors, not just one. Joe might get a pass because he had one of them, but Bill--who had five--might be flagged for a manual review.