Key takeaways
Shop for B2B contact data and you’ll find these three names set against each other in a hundred “X vs Y vs Z” guides. Most are written by one of the vendors, or by an affiliate paid when you sign up.
What they skip: Apollo, Clay and ZoomInfo do different jobs. Asking which wins is like asking whether you need a grocery shop, a recipe or a kitchen. See them as layers and the choice comes down to your team’s size, budget and way of selling.
Three different jobs
Apollo is the all-in-one value pick. It has its own database of more than 240 million contacts, basic email sequencing and a free tier. It’s the natural first tool for an early team starting outbound. Its coverage of small and mid-sized companies is often stronger than ZoomInfo’s, and its email accuracy is now on par for many uses.
Clay owns no data at all. It pulls from more than 150 databases through one interface. Its signature move is the waterfall: each lookup goes through several providers in turn until one returns a verified answer. Different databases have different gaps, so the combined coverage beats any single source. But Clay only pays off if you build the system. It rewards RevOps teams and overwhelms a small team that just wants contacts.
ZoomInfo is the enterprise dataset. It has more than 300 million profiles, intent data showing which companies are researching your category now, org charts and a large set of direct phone numbers. It’s also expensive, about $15,000 to $25,000 or more a year on annual contracts. And it’s complicated after fifteen years of acquisitions.
None of the three runs your outbound. Sending, inbox warm-up, coordinating channels, handling replies and booking meetings need more tools. I cover those in my comparison of AI SDR tools. So budget for the whole stack: a data source, an enrichment layer, a sequencer such as Outreach or Salesloft, and separate deliverability services.
What most mid-market teams miss
For most B2B software companies between about $1 million and $10 million in annual revenue, the right set-up is Apollo plus Clay. Apollo builds the target lists. Clay checks, enriches, scores and personalises them across several sources.
Together they cost around $5,400 a year: about $99 a month for Apollo and $349 for Clay. That’s less than a ZoomInfo contract, with better email accuracy, because you aren’t trusting a single source. The most careful teams use Apollo as Clay’s cheap first source and go to other providers only for the fields it misses.
Almost no vendor guide recommends this, because it doesn’t end with “buy our product”.
Which one for which team?
ZoomInfo’s value grows with your deal size. Clay’s grows with your willingness to build. Want every layer laid out at once? The stack builder does it in six questions.
Frequently asked questions
Is Clay better than Apollo or ZoomInfo?
It's a different category. Clay doesn't own a contact database. It runs lookups across 150+ databases (including Apollo and ZoomInfo) and lets you build custom enrichment workflows. It's powerful for RevOps teams that will put in the work to build it. For a small team that just needs contacts and sequences, it's overkill.
What's the cheapest good set-up for a mid-market team?
For most B2B SaaS between about $1M and $10M ARR: Apollo for prospecting (around $99/month) plus Clay for waterfall enrichment (around $349/month). That's about $5,400/year combined. It usually costs less than a ZoomInfo contract and gives higher email accuracy, because you're enriching across several sources.
When is ZoomInfo worth its price?
When you're selling to enterprise accounts with $100k+ ACV and complex buying committees. At that level, ZoomInfo's intent data (seeing which companies are researching your category), org charts and large direct-dial phone dataset really set it apart. Under about $5M ARR or sub-$30k ACV, its $15k-$25k+/year price is usually hard to justify.
Do any of these tools actually send outreach?
Not really. Apollo includes basic email sequencing. But none of the three handles full outbound: deliverability set-up, inbox warm-up, multi-channel coordination, reply handling and meeting booking all need more tools. They give you the ingredients. You still need a sequencer and deliverability stack to cook.
What is waterfall enrichment?
Sending each contact lookup through several data providers in priority order. The first source that returns a valid, verified record wins. If it misses, the next one tries. The gaps in one database don't overlap with another's, so combined coverage and accuracy both rise. Clay is built around this. Done right, it beats any single-source tool on coverage.
How accurate is the data?
In independent benchmarking, email accuracy for the major databases tends to sit in the high-70s to mid-80s percent range. That's above the danger line for high-volume sending, but not perfect, so teams sending at scale add a verification step. Data also decays fast as people change jobs, so freshness matters as much as size.
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