Does the preference change depending on if it is a personal purchase or a purchase for your company? Does the preference change depending on the budget you have?
Here are some examples of the different pricing options you mentioned where they do and don't make sense:
* I do 3d printing. There is a service out there that will "fix" issues with existing models, automagically. It bills based on credits and each fix of a model, costs some credits.
* Twilio charged based on usage, since that's how their costs work out.
* I subscribe to GSuite on a per-user-per-month basis.
Here is one example where two companies have made very different pricing choices:
* Cloudflare Access provides access to an unlimited number of servers based on a per-user-per-month basis. For a small business with say 1 system administrator and 50 servers, this makes sense. They'll pay for 1 user (call it $5/mo)
* On the flipside is Okta ScaleFT server access product. They charge per server, per month. So if you're that same small business, you're paying maybe $500/mo for the product.
One can argue either way makes sense. Cloudflare's more aligns with what a buyer wants to pay (less), where as Okta's aligns with actual costs (per server). However, in a case like this, the product provides a value in the form of employee optimization. So the value increases per employee/user, not per server. The buyer will be willing to part with more money, if the perceived value is higher.