Why We Buy - The Science of Shopping."
"Why We Buy" is about how people buy items in retail stores. But Underhill's lessons apply to buying software on the Internet, too.
Underhill mentions that a popular group of drug stores in Florida had magnifying glasses on chains, attached to the shelves. If you're selling online, don't use tiny type, and don't use fonts whose sizes are fixed by the web designers. Let people with bad eyesight use their web browsers to select larger fonts, whether they're using a Windows PC, a Mac, an iOS device, or an Android phone or tablet.
Underhill's studies have shown that the better educated and more affluent a consumer is, the more likely it is that that consumer will want to read what's written on labels, boxes, and jars. And perhaps on the EULA in your application, and on your web site.
Another interesting finding is that older customers prefer to receive instructions from somebody in their own age group. They don't like to be told how to do things by people whom they regard as kids. We all need to think through how we deliver that particular feature on our web sites. Perhaps it sounds cool to deliver your sales message in a young and trendy way. Perhaps such an approach won't appeal to older prospects.
As with every aspect of your sales message, you need to measure today's sales results, tweak your sales presentation, and measure again.