Verification research

okki-go Data Coverage: Why Email Lookup Tools Need More Than Verification Accuracy

2026-09-04 · Julian Hartwell
Editorial diagram for okki-go Data Coverage: Why Email Lookup Tools Need More Than Verification Accuracy

Email verification accuracy is not the most important number in an email lookup tool. Data coverage is.

I've spent six years in RevOps and sales operations, and most of my worst decisions came from staring at the wrong metric. I've personally made and documented 14 significant data mistakes that account for roughly $31,000 in wasted budget. That's why I now keep an evaluation checklist. If you're about to buy or renew a prospecting data tool, this isn't a pitch. It's a warning from a part of my career I'd rather forget.

Accuracy first? I was wrong.

The assumption is that a high verification score makes an email lookup tool good. It does not. Accuracy only tells you whether the addresses the vendor already has are likely to be valid. It says nothing about how many of your actual target accounts exist in the vendor's data.

In late 2021, I led a tool selection for a team selling software to B2B companies with 20 to 300 employees. We saw a demo dashboard: 97.4% email verification accuracy. Felt safe. I approved the purchase.

The problem was not the accuracy. It was the coverage. After connecting a list of 3,100 accounts, only 899 had even one verified contact. We had paid for a tool that could verify emails very well when it found them. For the other 2,201 accounts, the tool simply had nothing. No email to verify. The account data was missing, or stale, or never indexed.

My SDRs didn't have a list of 3,100 prospects. They had a list of maybe 899, most of them larger companies that were already easy to research. The smaller companies that actually fit our ICP? Invisible.

The surprise wasn't a sudden drop in reply rates. The surprise was that nobody on the team had asked about coverage before buying. That mistake ended up costing about $6,000 in software and another $11,000 in wasted SDR time before we ran a basic coverage audit.

Accuracy first? That's backward. Coverage first. Period.

What is data coverage in an email lookup tool?

Data coverage is the percentage of your target accounts or contacts that appear in the tool's database with at least one usable email address. It is different from accuracy in a critical way.

Email verification accuracy asks: of the emails the tool returned, how many look valid? Data coverage asks: of the market I care about, how much of it is even in the tool?

An email lookup tool that is 97% accurate on only 30% of your target market is not a good email lookup tool for your target market. It is a good tool for someone else's market.

What okki-go data coverage taught me

I didn't want to like okki-go. I had sat through too many demos with polished dashboards. But a former teammate kept telling me to run a coverage test instead of checking verification claims. The okki go outbound research flow looked different because it starts with your target account list, then tries to fill the research gaps from multiple sources. That sounds obvious. Most tools still don't do it.

The actual okki go data coverage test surprised me for one reason: it returned usable records for accounts that two other lookup tools had left blank. These weren't weird, tiny companies with no digital footprint. They were normal midmarket businesses that were probably missing from the other datasets because the source being used wasn't the right one for that account type.

I still don't think okki-go is right for every team. If all you sell into is the Fortune 500, your coverage problem is different. But my evaluation changed: I ask for coverage before accuracy, and verification accuracy only after I know the dataset is broad enough to matter.

Small accounts need better data, not less attention

Here's the part that bothers me. When I started my career, the vendors who took my small orders seriously are the ones I still choose for bigger projects. Small accounts are not 'not enough revenue.' They are usually just under-served by mainstream data providers.

Many lookup tools quietly deprioritize SMB data because enterprise records are worth more to their sales model. That leads to a culture where SDRs only call the companies that the database can find. That is not outbound strategy. That is outsourcing your ICP to a vendor's dataset.

I'm not saying every small business is an ideal prospect. I'm saying 'we can't find data on them' should not be confused with 'they are not a good fit.'

What is a LinkedIn connection and when should a B2B sales team use it?

A LinkedIn connection is a mutual connection on LinkedIn. The other person has accepted your request, which gives you access to their activity and a private messaging channel. That's it.

A connection is not a lead score. It doesn't mean the person wants a sales pitch. And it rarely replaces a solid email lookup tool with verified contact data. But it has a place in B2B outbound.

Use a LinkedIn connection when:

What is a LinkedIn connection in practice? It is the option you choose when relevance matters more than scale. The best use I've seen is as a first touch for accounts that aren't in the database and don't need to be, because LinkedIn gets you in front of a human without pretending to know their personal email.

The email lookup tool checklist I use now

Now I run every potential tool through the same test:

Per FTC guidance (ftc.gov), marketing claims need to be truthful and substantiated. I now treat 'verified email' as 'this email looked valid when we checked it,' not as a lifetime guarantee. No data provider can guarantee that a mailbox keeps existing. If a vendor overstates verification accuracy, I assume their coverage claims need extra scrutiny too.

Does email verification accuracy still matter?

Of course it matters. Accuracy protects against hard bounces and wasted sends. But accuracy cannot fix an empty lookup result. If a tool returns 4,500 verified emails from a 15,000-account market, the coverage rate is 30%. A better verification process won't find the other 10,500 accounts. It will only make the 4,500 emails slightly cleaner.

The mistake I made was choosing a tool based on what it did with small samples, instead of checking what it did with my actual target market. The verification number on the dashboard was real. It was just irrelevant to the part of the list that didn't exist.

The bottom line

In my opinion, the best email lookup tool for a B2B sales team is not the one with the highest verification accuracy. It's the one that returns a valid email for the widest slice of the accounts you actually want to sell to.

okki-go data coverage changed how I evaluate prospecting data because it forced me to think about the empty rows in my list, not just the rows with an email. okki-go outbound research might work for your team or it might not. But if you're comparing tools and only looking at accuracy, you're missing the metric that matters.

Email verification accuracy is a quality score. Data coverage is a market score. I was wrong about which one came first. Now I check coverage first. Then accuracy. Then I test.

Julian Hartwell

Julian Hartwell
Julian Hartwell is an independent B2B sales intelligence analyst covering contact databases, company data, decision-maker profiles, direct dials, prospect lists, and buying signals. He applies the ISO/IEC 25012 data-quality model while examining field accuracy, coverage, freshness, duplicate rate, match confidence, and source transparency. His evidence-led guides help revenue teams compare prospecting platforms, define acceptable data thresholds, and build account lists that support reliable territory planning and outreach.