If a user on an e-commerce site is in the middle of a purchase process when they leave to another part of the site, or perhaps leave the site completely, what information should be retained if they return to the checkout process? Should it keep their payment information? Should it ask for some sort of confirmation like "what are the last four digits of your payment card?" in order to retrieve that? Should it completely forget everything and just go back to a full cart as though no checkout attempt happened?
General rules of thumb:
- it should not save any personal info unless I asked it too (such as credit card info--people don't trust a site that is storing their personal data without their permission)
- it should save non-personal info for my convenience (such as my shopping cart--if it's saved, I'm more likely to finish my purchase)
I would absolutely save the users cart.
You could do this by checking to see when the cart was last updated in your database for example or cross-referencing the User ID with the Cart ID to check if the user has left the site but with a cart full of goodies.
Then - you have a few options:
- Save the cart - and re-instantiate the cart when they come back / log in
- Save the cart - and email them later to let them know that you saved the cart
- Save the cart - and don't tell them anything (this is what you wouldn't do)
People, once they have left the site - just tend to forget completely that they even visited your site in the first place. It will absolutely help your business / shop if you at least remind them or let them know that if they abandon your cart, it will still be there when you get back. The best way, IMHO, is by email.
DA01's point about not retaining sensitive information is also valid, only retain their cart items.