Why YSK: If you were going to buy from a smaller online brand anyway, this often knocks 10-20% off for zero effort, and if nothing comes you've lost nothing.
How it works: most independent online shops run on Shopify or something similar. Once you've entered your email at checkout and left without paying, the platform logs it as an abandoned checkout (Shopify does this after about 10 minutes of inactivity) and sends an automated "did you forget something?" email at a set delay, usually somewhere between 1 and 24 hours later. Shops can attach a discount code to that email so the link takes you back to your basket with the discount already applied. Not every shop does it, but plenty do, because a discount is cheaper than a lost sale.
So: basket, email, close the tab, check your inbox (and spam) the next day. It doesn't work on Amazon or the big retailers, it's the independent brands. Works best if you're not already a customer.
Source, Shopify's own instructions to shop owners on setting this up: https://help.shopify.com/en/manual/discounts/discounts-for-abandoned-checkout-recovery-emails
Just got an email from refillable brand Wild about this new collab with Hello Kitty and thought I'd share. From experience they do limited editions quite often but they often run out.
For anyone who doesn't know it's refillable deo and lip balms with cases you keep. They did a Miffy collab which I bought and have been using ever since, it's a lovely eco product and now with Hello Kitty I've had to buy a whole lot more lol.