What waterfall enrichment actually costs

A miss is free. That is the part the pricing pages bury and it decides most of what follows: at Clay, BetterContact, FullEnrich, Datagma and Prospeo, credits come off your balance only when a provider actually returns a result, so a cascade that tries eight sources and succeeds on the eighth costs exactly what a cascade that succeeds on the first costs.

Which means the question you probably came here with, whether stacking more providers will quietly drain your credits, has a boring answer. It will not. The money goes to two other places, and one of them is a list that is too small.

The billing rule, in each vendor's own words

Five companies selling waterfall enrichment publish close to the same sentence.

Clay, in its own documentation: "You only pay credits for the provider that finds a match, making it one of the most credit-efficient ways to build email coverage at scale." BetterContact, in its pricing FAQ: "No, there are no credits charged when an email or mobile phone number is not found." FullEnrich: "credits are only deducted when a verified email or phone number is actually found... you never pay for redundant lookups." Datagma: "you only pay when we find a verified email or phone. No match = no credit used." Prospeo: "you are only charged credits when a valid result is returned."

All five read on 4 September 2026. All five sell the product they are describing, which is a reason to check the claim rather than dismiss it, and on this particular claim the incentive runs the honest way: a vendor that billed for misses would have to say so somewhere in the credit documentation, and none of them does.

So the arithmetic behaves in a way the word "waterfall" hides. Under pay-per-hit, the price of a successful row does not depend on how many providers failed before it. A twenty-provider cascade that lands on provider nineteen costs the same as a two-provider cascade that lands on provider two.

Apollo charges for the near misses, and says so

One vendor's rule is different, and Apollo states it plainly in its own FAQ, read on 4 September 2026: "You use credits whenever Apollo or a connected data source successfully returns an email or phone number, whether or not it's verified. You aren't charged if a source can't find any data."

Read the middle clause. Elsewhere on the same page Apollo gives the familiar version, "Credits are only charged when a source successfully returns data, so a run that finds nothing costs nothing," and both are true at once, because finding nothing and finding an unverified address are different outcomes.

The consequence is in Apollo's instructions for running the feature: "Searching for a verified email may cost more credits, depending on the number of providers cycled through during enrichment. Enrichment continues until a verified email is found. Connected providers charge credits for each unverified email found before locating a verified email."

So if you require verified email, a provider that hands back an address which fails verification still bills you while the cascade carries on. A total miss is free. A near miss is not. And if an administrator has connected an optional validator, Apollo says that "will also charge credits to validate found data," which is a second charge on the same row.

No other vendor's documentation read in this research describes a billed intermediate result. If you run waterfalls in Apollo with verified email required, that is the line item to look for, and the credit types Apollo meters are worth knowing before you turn it on. Apollo does at least show you the bill in advance: it says every run gives you a credit estimate before it starts.

Clay meters two things, and the expensive one is not the one you are watching

Clay's pricing page publishes two separate ladders, and this is where most of the confusion about waterfall cost actually comes from. Actions and data credits are priced independently and expanded independently.

Read on 4 September 2026, annual billing. The expansion prices sit next to each other on the same page and they are not remotely alike. On Launch, another 180,000 actions a year costs $54 a month. Another 30,000 data credits a year costs $113 a month. Work it out per unit and a data credit costs about twelve and a half times an action: $648 a year buys 180,000 actions, so an action is $0.0036, while $1,356 a year buys 30,000 data credits, so a credit is $0.0452. A waterfall spends the expensive one.

The Free plan includes multi-provider waterfalls, so the feature is not what you are buying when you upgrade. Credit volume is. Free gives you 1,200 data credits a year and caps tables at 200 rows, which is the real ceiling rather than any feature gate. We worked through the full arithmetic of what it costs to run a list through Clay separately, including why the AI research column tends to be the line that hurts.

A thousand rows, priced from Clay's own provider table

Clay publishes both the coverage and the per-find price of every provider in its work-email stack, so the run can be priced end to end. One assumption before the table, and it belongs in the open: Clay does not say whether those percentages are share of the whole list or share of whatever is left when the row reaches that provider. This reads them as share of the whole list. Change the assumption and the row counts move; the ordering of the marginal prices does not.

The blended column is almost flat. It goes from $0.328 to $0.341 across the whole stack, which is why nobody notices anything. Look at the last column instead.

Wiza fills 20 rows out of a thousand at a dollar each. That is two to five times what every other provider in the stack charges per find, for two points of coverage. If an incremental filled contact is worth less than a dollar to you, the cascade should stop before Wiza and not after Enrow, and Enrow being cheap is exactly why the blended average never warns you.

The lever the table actually supports is ordering by published price rather than by the vendor's default position in the stack. That is a five-minute configuration change and it is worth more than any coverage claim on the page.

The small list is the expensive one

Every dedicated waterfall vendor sells credits inside a fixed monthly plan. BetterContact publishes Starter at $15 a month for 200 credits and Pro at $49 a month for 1,000. One credit is one found and verified email; a mobile number costs ten. Both read on 4 September 2026.

Because misses are free, a run spends credits equal to the rows it fills, not the rows it attempts. Which produces this.

Match rate: 98%, from Cleanlist's own benchmark. See below.

That 98% is the only waterfall figure found anywhere in this research that states both a sample size and a verification rule. Cleanlist also sells waterfall enrichment, so treat the number as the vendor's best case rather than as a measurement.

The shape is what matters. A 300-row list pays 3.3 times more per filled contact than a 1,000-row list, at the same vendor, the same per-credit price and the same match rate. Nothing about the waterfall did that. Two hundred and ninety-four credits do not fit inside a 200-credit plan, so you buy a plan sized for more than three times the volume you use.

So the rule of thumb, if you want one line to take away: under about a thousand rows a month, price the plan floor before you price the provider. Above that, the provider order is what matters. If you are enriching a few hundred rows a month, the credit ceiling above you is the number to price against, not the cost per contact. The break-even everyone looks for is a step at each vendor's published tier divided by your expected match rate, and it is not a smooth curve.

The coverage number everybody repeats

There is one claim in this space you will meet before you meet any of the above: single-source enrichment matches 40% to 60% of a list, a waterfall matches 80% to 95%. Google's AI Overview on this query prints that range and attributes it to an aggregate of six pages.

No method for it was found. Not on the vendor pages, not in the AI Overview's own citations, not in search. What exists instead is a set of claims with no denominator: Clay's "150+ databases" and a customer quote about tripling an enrichment rate, BetterContact's 98.5% verified discovery, FullEnrich's 80% and more, Apollo's own beta lift figures from two months of data. Every one is published by a company selling the thing it measures, and not one states how many contacts were tested, against what ground truth, or when.

Cleanlist's benchmark is the single exception on method: 500 B2B leads stratified by industry, seniority and company size, weighted toward North America, with coverage counted only after a deliverability and connectivity check. It reports 98% verified email through a 25-provider waterfall against 70% to 80% for a single source. It is also self-published by a company whose core product is a waterfall, self-verified, and not replicated by anyone. The best independent-looking alternative, a blog post claiming a 10,000-contact European test, carries no author, no institution and an affiliate-commission disclosure sitting above the numbers.

So the honest position is that the direction of the claim is plausible and its size is unmeasured by anyone without a stake. We have written before about the gap between claimed and measured accuracy across this category, and waterfall coverage is the same problem one layer up.

When a waterfall is the wrong purchase

Three cases, and none of them is about the mechanic.

Your list is small enough that the credit plan dominates the arithmetic. Then the cheapest correct move is to fill fewer rows deliberately and stay inside a $15 tier, or to run the free tier of one provider and accept the coverage you get.

You need verified email in Apollo and your providers return a lot of unverified guesses. Then the intermediate charges are real and worth measuring for a month before you scale the job.

Or the rows you are filling are not worth what the last provider in the stack charges to fill them, which is the ordinary case and the one nobody prices. A dollar a contact is fine if the contact is right. It is a bad deal for the tail of a list you have not checked, and the fix is upstream of enrichment: fewer rows, chosen better, then enriched.

Tamozo sells exactly that, so read the last paragraph with the discount you would apply to any vendor writing about its own category. The numbers above are all from other people's pricing pages and they are all dated.

Prices and quotations in this article were read at source on 4 September 2026: Clay's pricing page and work-email documentation, Apollo's two waterfall knowledge-base articles, BetterContact's pricing and FAQ, FullEnrich, Datagma, Prospeo and Cleanlist's benchmark. Both Apollo pages had been updated within hours of that reading, so check them again before relying on the credit rule. Where a coverage figure has no published sample size, this article says so instead of repeating it as data.