As a black-hat SEO tool, link farming has been around since approximately the morning after Brin & Page submitted their seminal thesis. It was a bad idea to begin with—demonstrating a poor appreciation of the math behind the PageRank algorithm—and it's become an even worse idea since Google et al started actively pursuing and penalizing link farmers.

The question on the table before me, though, is this: when is a link farm a Link Farm?

I run a small network of websites. I call it a network because they all run on the same DotNetNuke installation; topically, the sites have little if anything in common. All the sites are moderately successful in their own right.

In fifteen minutes, I could drop an unobtrusive widget on every page of each of these sites that would link to the home page of all the other sites (that's about a half-dozen links). I'd put it in a box entitled something like Other MyNetwork Portals, and it would produce thousands of additional links to each of my home pages from pages that actually have a little juice to offer, even if they aren't topically related.

So here's the million-dollar question: should I do it?

I have to stress that these sites are in no way gimmicky... sure, I've gone out of my way to make them as search-friendly as possible, but they are all useful, attractive websites that provide plenty of original content relevant to their respective themes. At the same time, though, it's probably fair to say that these new cross-links probably wouldn't add a great deal of value for site visitors, since each site is so topically distinct from the others.

I might give my whole network a nice boost in the SERPs. Or it might have no effect at all.

OR Google and the other engines might decide my network is a Link Farm and ban the whole thing, destroying my business.

Any thoughts?