Push notifications. Apps have them on by default, websites have them off by default. 100% of Temu's valuation is because they pester users all the time with nudges to buy stuff, which works.

Normies don't turn off notifications. Over the last few years all my relatives have picked up smart watches, (thanks to cell carriers upselling them hard during phone replacements) and in any given conversation at family events they'll be glancing at their wrist every 100 seconds.