What ways are there to store information about an anonymous/guest user in a database?

Question

Our application has an online shop among other features, and users are normally requested to register before completing a sale, creating a unique customer_ID in the

Answer 1

I would assign a unique Customer ID to save the data, and then on future purchases that the same anonymous purchaser makes you could look to see if the same email address and/or first line of the address and post code already exists. If you ask for a phone number, compare that. Basically you need something fairly unique whilst getting rid of possible errors (eg. only looking at first line of the address - it's very likely that there is more than one 123 Main Street! But there will be only one 123 Main Street with post code ABC123).

Once you know this, you could automatically create them an account - sending the customer an email saying that you've noticed that they purchased previously, and to save them time use this email address and this automatically generated password. When they login for the first time, do a quick security check (maybe value of last invoice), then let them check their details. You could even do this during the checkout process. I think by showing that you can save them time by doing it automatically could be a bonus.

If you don't want to do this, then it's possible to set a cookie, though you'd have to warn the user if you are trading from within the EU (cookie laws).

The problem with someone having different email address and postal address, could be that they order for business, then they could order for personal use (hard to say as we don't know what you're selling).