Quantity can definitely be a trigger for upgrading. That's why Blinkist second paywall argument is "Unlock 3000+ titles". The message is the following: "If you doubt about the value of the app, look at all the content available in the premium plan. You won't regret it."

Hily has a distinct approach to paid plan quantitative benefits. They use a unique paywall: without Boost / with Boost. A picture is worth a thousand words.

See here with Bumble: buy Spotlight credits and get up to 20x more profile views.