That's the main reason I don't prefer to shop online. I like to browse a limited selection and be surprised by something I wasn't even looking for.
Etsy used to have a feature where they could show you a random assortment of items for sale on their site, but I just checked and they don't seem to have that anymore. They are a site for crafters to sell the things they've made, so doesn't really answer your question, but it is the only site I know that tried something like that.
I spend a lot less money on books for myself now that I'm purposely limiting myself to ebooks. However, I am also spending a lot more money on books for my kids, since we have a local independent bookstore that is both within walking distance of the music studio and open when we're in the area for lessons. I admit to having a stack of unread books that I've purchased from there for myself; recently, I checked one of those books out from the library to read on my tablet and I have a feeling that's the only way I'm going to get the rest of them read!