[mateuszbuda]

At https://scrapingfish.com/ we have both options, usage based https://scrapingfish.com/buy and subscriptions (monthly unlimited requests plan) https://scrapingfish.com/unlimited. Despite subscriptions being cheaper option per request, usage based is way more popular. Only less than 10% of our users have subscribed to unlimited monthly plan. I guess usage based plans give users more control over how much they spend or maybe they simply don't want to subscribe to another service.

[telepathy]

Residential IP bandwidth is a commodity priced per GB. The rest is available OS for free. This isn't a SaaS exactly.