What does pay per successful request mean?

Pay per successful request means the meter only runs when you get the page. A blocked attempt, a challenge page or a timeout costs nothing, and you are not billed for retrying it.

It sounds like a small billing detail. On protected sites it is a large one, because the failure rate is the whole question.

Why it changes the arithmetic

Consider a target where roughly a third of attempts get refused, which is unremarkable for a well-defended site.

Billed per attempt, fetching ten thousand pages means paying for the failures and then paying again for the retries, so the real cost is well above the sticker price and, worse, it is unpredictable. A site that tightens its protection raises your bill without changing what you collect.

Billed per success, ten thousand pages costs ten thousand successes. The failure rate becomes the provider's problem, which also aligns the incentives: a provider paid only for successes has a reason to keep succeeding.

Bandwidth pricing has the same issue in a different shape. Block pages are still bytes, so you pay for them, and a block page delivered instead of a product listing costs you money and returns nothing.

What counts as success

Worth checking, because the definition is where the value sits. A provider that counts any HTTP 200 as a success is not offering much, since a challenge page frequently arrives with a 200. The useful version counts a request as successful when it returned the actual content.

How it interacts with cost per page

Pay per success is separate from how much each success costs. Most providers price by request type, since a rendered page consumes vastly more than a plain one.

Zenrows uses credits with published multipliers: one credit for a standard request, five for JavaScript rendering, ten for a residential proxy, twenty-five for a protected request. Those numbers are the reason choosing the method per URL rather than globally is worth doing. Rendering everything by reflex is a five-times bill for no extra data.

Where Zenrows fits

Zenrows bills on success, and pricing documents the credit model and multipliers rather than leaving effective cost to be discovered from an invoice. Credits are shared across Fetch, Extract, Batch and Browser Sessions, so moving work between primitives does not mean moving between plans. The free plan is 5,000 credits a month, recurring, with no card required.