Most of what Bob says here is extraordinarily good advice, and goes for you whether you're selling software, a subscription service, or whatever.  I've always been skeptical of one bit of it though:<p><i>Not being able to find a physical address, telephone number and business name within one click of the home page is a deal breaker for me when shopping for software: most people feel the same.</i><p>I trust Bob's gut right to the colon, but I need data to trust his gut after it, and he doesn't have it.  Empirically, I sell to plenty of people without any of these things.<p>(Incidentally, the trouble with putting these trust signifiers one click from the home page is that normal users don't really care about any link from the home page aside from the ones which let them complete goals.  If you're going to have a home number in the hopes of motivating people to believe you are a Real, Trustworthy Business, then put the thing prominently by decision points like your buy button.)