>A real world analogue would be if I tried to leave a store and someone blocked my way to try and make me buy something.

That'd depend on the implementation behavior. If it's using window.onbeforeunload, yeah I guess it's kind of like someone blocking you when you try to leave, although you can easily walk around them (on most browsers if you try to close the tab and the modal shows up, and you try to close the tab again it will override the modal). However, there's also another type where it tracks the location of your cursor, and shows a popup when it leaves the content area (indicating that your mouse is going to close the tab or go back). In that case it's not really blocking anything, and much more analogous to a salesperson saying "before you go" as you're walking out the door.

Either of these behaviors is equivalent to someone standing in front of the door and trying to harass me when I leave.

Which is a solid ‘no thanks, not coming here again’ from me.

> much more analogous to a salesperson saying "before you go" as you're walking out the door.

I would try to avoid going back to that store.

I would never go back to that store and I would tell my friends not to shop there.

But assuming it’s just a div that appears when you mouse off at the top, it doesn’t actually do anything to stop them. It’s not outrageous for a shopkeeper to say “don’t go!” or something like that as you’re leaving.

It’s annoying and tacky but it’s not analogous to being held hostage.

In the olden days, a website could pop up a dialog box that would lock browser interaction til it was dealt with. It was abused. A lot. This was way prior to 2012 tho.

You've never seen this? When someone clicks to close a browser tab you can stop the tab from closing by adding a handler to the onbeforeunload() event.

And that can be bypassed by closing the tab again.

Yup, pretty terrible.

2012. A modal dialog was probably a javascript alert(), which at the time was model for the whole browser and would prevent navigation until dismissed.

I just tested with an older version of firefox (10.0, released January 31, 2012), and it had non-modal alert() dialogs.

While I agree, do remember that some patterns can and do extend to the physical.

Many stores do indeed make it hard to leave without buying, for example by having no direct route to the exit: you have to squeeze through the tills awkwardly. It's probably in the name of loss prevention, but it's also a disincentive to leave without a purchase.

Actually, nearly everything about a supermarket is carefully designed for extracting money from you, from product placement, to layout, need to have a loyalty card to access discounts, even perhaps having discounts in the first place (as opposed to selling at a lower regular price), multipacks driving food and packaging waste, etc etc etc.

Best Buy used to do something similar in their retail stores to paying customers. A bouncer at the exit would usually stop people and check receipts against the merchandise they were leaving with. It's a great way for a company to show that it has no trust for its customers and that it hopes they don't come back.