I can recall a small handful of times when I decided to price shop around on the Internet for a particular product. I went onto Google Shopping, entered the product name, and started browsing the sites that were selling the product for the lowest prices. I chose the one that appeared the most reputable and didn't send up any red security flags as I started the checkout process.
While I completed my purchases from these individual sites, I had to create a customer account. I had to supply registration information, and, in order to complete my order, I naturally had to provide shipping and billing information as well, which included for some of them my CVV. Each time, the product I had ordered showed up in the mail in the next week or two. (I don't what happened to "Allow six to eight weeks for delivery", but I'm glad those days are gone; I'm from the super impatient MTV generation.)
Of course, I did business with these sites for the single product that I was looking for, and they sent me the product I ordered in the condition promised. They didn't do anything incorrectly. However, once I had completed each of these transactions, I was pretty sure that I wouldn't be ordering anything from them again. It's nothing personal...my purchase was just a means to an end: they had something I wanted for cheap and I bought it from them. The experience of shopping on their site didn't compell me to return to shop more.
The problem here was that, in each of these cases, when I returned to the sites, none of them offered me any closure. If I want to stop being their customer, there was no way for me to remove my information from their system. There was no "Cancel My Account" option that would scrub my shipping and billing information from their customer database. (It was also unclear to me in most cases just how much of my information they had chosen to store; some of them might have kept my CVV despite the PCI guidelines)
The reason they're doing this is simple: they want to make it easy for me to return and purchase more stuff. If there's even a chance that I'll return one day and attempt to make another purchase, they don't want me to be deterred by the inconvenience of having to enter my information again. Why not err on the side of caution and just keep my account there in perpetuity?
Another reason is the potential for vendor lock-in. They're hoping that the inconvenience of having to enter that information on another site might give them an edge over other competing sites that don't already have my information.
This sounds like a bad idea. People are sensitive about their personal information, particularly when it's financial. They're wary about to whom they're going to provide it. Hanging on to customer data in an effort to keep your customers returning to make subsequent purchases seems like sticking your thumb out between the index and middle finger of your closed fist and saying "Got your nose!" It also seems lazy; instead of competing in a creative and intelligent way, you're just holding a customer's data hostage in the hopes that it will provide them a net benefit that will help you.
One other important reason e-commerce companies are so tight-fisted when it comes to customer information: after the dot-com bubble burst, a lot of tech companies found that the only asset they had with any residual value was their customer data. There's value in the data. Of course, that's no reason to refuse to let customers remove their data. To make decisions based on the assumption that your company will eventually fail is a violation of the continuity principle. That is to say, you shouldn't let the "what ifs" cloud the day-to-day operating decisions of your business. You're supposed to be adding value for your customers, not planning your exit strategy.
Here's a progressive idea: let customers delete their accounts. Give them a clear and obvious means of doing it somewhere in the interface of your site. When you're trying to convert them from anonymous customer to registered customer, tell them that you'll provide them the option of removing their data when they decide they're done. And when they choose to remove their data, actually delete it...don't just provide a friendly message letting them think you've deleted it when you're really just copied all of it into an archived table.
Now, I think this is a great idea, and a good feature that more sites should offer. However, before actually trying to do this, you need to give what you're doing some thought. Take the following view function:
def cancel_view(request):
request.user.delete()
In most cases where there aren't dependency issues lurking in your model relationships, the Django delete the user and all of the data associated with them. That's one nice thing about the ORM: it crawls the model instance hierarchy and deletes everything from the bottom up, instead of coughing up foreign key constraint errors or leaving some records orphaned in other tables.
In some cases, however, you don't want to delete everything. Take the OrderItem model we created in Chapter 5: it contains the quantity and unit price at purchase time for each item sold on the site. This is tied to the Order model, which might contain shipping or tax charges for each order. And finally, this is tied to the User model. Which means if you delete a customer, you delete their order information as well.
You don't want to remove this. This is part of your financial records. You may keep a fastidious paper trail, printing up packing slips and invoices for each order that you ship, and that might be sufficient for bookkeeping purposes. However, around audit time, it will behoove you to have this information in the database.
Exactly what you choose to store, and how to choose to migrate the information, is based on your own business requirements. At the very least, if you're storing credit card information, I would remove that completely at a customer's behest, particularly because it has no value for you once a customer decides they'll never authorize you to bill them for anything again in the future.
If I had to guess: most customers won't end up ever deleting their information. Even the customers that show up once, place one order, and ne'er return probably won't even go to the trouble of deleting their data. It's more about the offer up front, to ease those customers that are uneasy about providing the information in the first place. Think of it as falling under the same umbrella as your store's "Return Policy".
