The first thing I tried is, does middle-click open a new tab properly? Turns out it does, which already puts this site above average compared to a lot of online shops I use, simply for not breaking a standard browser feature!
Ways I've seen it done wrong include middle-click/Control+click not working at all, because the links are some kind of onclick="javascript:" monstrosity, or the link working but some script in the background also redirecting the page on the tab I originally clicked on.
(I can understand some kind of "flow control" during the checkout process to stop you from double-submitting the "place order" request. But not when I'm browsing the products, and sometimes want two tabs open side by side to compare things.)
Ways I've seen it done wrong include middle-click/Control+click not working at all, because the links are some kind of onclick="javascript:" monstrosity, or the link working but some script in the background also redirecting the page on the tab I originally clicked on.
(I can understand some kind of "flow control" during the checkout process to stop you from double-submitting the "place order" request. But not when I'm browsing the products, and sometimes want two tabs open side by side to compare things.)