Two examples of many, to illustrate there's more to it than playing Malcom Gladwell with the price points:
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1. A software company that most people here would recognize (and many use) asked me to find out why corporate/enterprise users weren't upgrading from the free and low-cost plans to the upper tiers. After extensive research and customer interviews, I identified five main benefits their enterprise users were getting from the platform.
The twist: Four of those five benefits were available on the free plan. And the "premium" features on the top plans were of no use to them. No wonder they weren't upgrading.
Soon after, the company overhauled their pricing plans to capture more value ($$) from the benefits they provide.
This was a major breakthrough for them and led to fantastic outcomes.
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2. Another software startup, smaller than the one above but still recognizable by a good fraction of HNers, was losing potential customers because their pricing tiers were based on # of servers. Because 1) EC2 and Docker were becoming a thing at the time, so pinning the price to "number of servers" resulted in some absurdly high quotes for not-so-large teams, and 2) the legacy/incumbent providers pinned their pricing to data volumes, so the people who wanted to switch found it hard to compare pricing and see that this company's plans were a better value.
We changed the pricing to be based on data volume and designed the tiers to be a bit lower than the big incumbents and to not encourage current customers to downgrade.
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And sure, while this was all going on there were designers and product marketers busying themselves with optimizing the pricing pages for conversions. However, a good outcome for them would be a 5–10% increase in signups, whereas the outcomes from the two examples above were measured in seven-figure increases in ARR and VC rounds.