Why? Well recently Matt Cutts, Google's Principle engineer, has mentioned that Google could well be factoring page response time in their organic search rankings in the future.
The impact of this change (ranking based upon how quickly a site comes back with a page to the user or the search engine spider) is that popular sites with slow pages could....
- Find themselves pushed down the page in Google, etc. or even disappear from the first page entirely
- Have to spend more on their SEO efforts or step-up their pay-per-click advertising to ensure they get prominence on the top of search results*
- Have to spend more of their development and testing efforts on Volume & Performance efforts - in turn adding to project timescales
- Bring hosting Service Level Agreements further into the spotlight
(*You try explaining to your boss why you're having to spend loads more on your Marketing budget because your site slipped down the results for key search terms)
So... with page performance becoming a more important factor, are you already measuring your page response times and comparing them against those of your competitors?