For us almost no new sites are stand alone any more.
Site owners are becoming more aware about the value and potential of adding an online store and payment facility to their sites.
Web users are much more inclined to buy online than five or ten years ago. Still there are many who don’t but those who do are much more likely to do it again having done it once.
This is possibly why so many online stores offer huge value, discounts, free delivery and other rewards to new customers. Simply to create the initial interaction and purchase enabling on-going follow up by the vendor via email.
When you buy online you are agreeing to the company contacting you again… generally.