tedster - 5:36 pm on Mar 8, 2012 (gmt 0)
what would be the effect of redirecting these invalid URLs to actual valid pages?
I've seen companies try this. At best, it did nothing - a waste of time. However, at worst, the liability is saying "Yes, we want to be associated with this crazy, manipulative, low quality network of websites. We validate these links."
If the bad link comes from a good quality site and if it is getting clicks, then asking them to fix the link is the best step. For a good quality site doesn't correct their bad link, in that case (only) I might consider a redirect. But that would usually be rare. These bad badlinks usually do come from shady places ;(