Many people is trying to setup a website and capture a sale immediately but they aren't doing it in the right way. You need to build an awareness so you can get new people into your website, you need to nurture relationships in order to get them to purchase from you, and you need to build trust over time in order to keep them coming back for their second or third purchases.
Most business out there focus on just awareness and hope they will gain a lot of sales, but its just doesn't work like that. People think they're gaining trust from every buyer they have, but that doesn't happen when you have a less than amazing company, so you need to focus on all 3 points if you really want to see your success compile and flood your business with profits.
If you want to be successful online or offline, you need to build awareness through marketing and advertising, nurture relationship with current and future buyers, as well as build up your trust within the community. If you can do all of these three of these things you will definitely be successful overtime.