Alas, we failed. Our theory was that what people liked best was recommendations from their first- and second-degree network (followed by a few other kinds of information). This worked really well if you had a relatively dense social network in the app. E.g., you could ask your exact question and get back replies from your friends and their friends. Inevitably a few friends and FoaFs would have useful approaches for something as common as mattresses. So toward the end of our seed money we were working hard on network infill and it was looking good. Then Facebook drastically changed the sharing rules, tanking our growth numbers just as we were looking to raise money. RIP and c'est la guerre.

The site I like best these days for purchase decision support is Wirecutter. Here's their mattress guide, which seems sensible to me: https://thewirecutter.com/guides/buying-a-mattress/