Nosto

Nosto is used mostly by mid-size online stores to personalize what shoppers see. Its best-known feature is product recommendations: blocks such as "customers also bought" or "picked for you" that are filled by its algorithms from browsing and purchase data, with rules a merchandiser can adjust.

Beyond recommendations it sorts category pages per shopper, runs on-site search, shows pop-ups and gathers user content such as customer photos. Teams often add it to Shopify, BigCommerce or Magento stores through a ready integration, then place recommendation slots on product, cart and home pages.

Ask how it measures the sales it credits to recommendations, since attribution methods differ between vendors. Check how the slots load on mobile and whether they slow the page. Start with a few placements and test them, instead of filling every page at once.