Dashes vs. underscores in website URLs

As one of the design decisions made when the GigJunkie website moved to MVC world, we decided to adopt Wikipedia styled URL naming by substituting spaces with underscores, instead of dashes. Some debate was thus unleashed when one of us discovered Google’s Matt Cutts’ article that showed this may have created an unforseen hindrance for our SEO goals. Another SEO article only added fuel to the fire as we now tried to figure out with our own testing if the discoveries dictated in these articles still held, i.e. that dashes were, by article and the published evidence, more index-friendly than underscores as replacements for spaces between words in URLs. I ended up starting to read the mantra of search engineers, the Stanford-published document that started it all, as well as another article on the PageRank concept in the seemingly hopeless quest to make sense of it all…

Perhaps I’m just too tired from the day, so I’ll put these on hold till tomorrow when I can figure out some sort of metric for weighing the impact (if any) of our design decision.