Is It True, Faster Sites Sell More Stuff?
bigstartups.com
bigstartups.com
Also possibly there is no point in worrying about the faster aspect until you have managed to do the selling -- which from what I hear is hard! Focus...ignore peripheral issues.
It is entirely a question of perception. Having launched a commerce site, and monitored the heat maps and conversion rates closely, I have seen it first hand. A snappy site gives the customer the impression that we are professional and know what we are doing. This increases their confidence in our company, and the likelihood that they will buy our product. When we had performance issues, we watched conversion rates drop. Doing something as simple as asynchronous loading of javascript for our job calculator (on a commercial printing site), had an immediate effect on conversions and revenue.
So, yes, faster sites definitely sell more stuff.
And speeding up a web-site/app that is slow is always harder than building one that is fast, so better delegate that task to a pro.