SevenCubed - 4:18 am on Feb 16, 2011 (gmt 0)
I'll assume you are directing that comment at me because I am actively posting in other threads at the moment, but you could have been more specific about who you are debating.
If you could even remotely understand the depth of potential issues that are resolved by validated code you might understand better. But I will not waste anymore time on the matter. I have nothing to prove to anyone. The OP said "your single best SEO strategy" and that is mine. I send my sites out into the wild built for endurance not for the popularity game.