How to Test Direct-Dial Connect Rates Across Data Vendors

A rep who has a great week dialing numbers from one vendor will credit the vendor. A rep who hits three wrong numbers in a row from another will blame that vendor, even if the sample is five calls total. Both reactions are understandable and both are unreliable. Treat a freshly enriched number like any other fresh lead and contact it within the same business day¹; timing affects connect rates as much as the underlying data does, and a test that ignores that will draw the wrong conclusion.

Pull the same one hundred to one hundred fifty target accounts and split the contacts across data-vendor buckets, or randomly assign a source per contact if you're already pulling from more than one vendor. The point is to avoid confounding good numbers with good accounts: if one bucket happens to contain your easiest-to-reach industry and another your hardest, the result will reflect the account mix, not the data quality you're actually trying to measure.

Define what counts as a connect before the first call goes out: a live human, not voicemail, not a wrong number, not a gatekeeper who won't transfer. Place the calls through a consistent system, KrispCall works well here, so every attempt logs the same way regardless of which rep dials it, and use WhatConverts to tag each call outcome back to which vendor sourced that specific number. A spreadsheet someone updates by hand drifts within a week; a logged system doesn't.

A few things to check before trusting the result:

• Time of day and day of week should be roughly balanced across buckets, since dial timing swings connect rates on its own.
• Use the same reps across buckets where possible, since skill variance between callers can be larger than the data difference you're trying to measure.
• Make sure the sample is large enough that one unusually good or bad day doesn't swing the whole result.
• Re-run the test periodically, since a vendor's accuracy changes as their underlying sources refresh.

If one vendor's numbers connect meaningfully more often once you've controlled for timing and account mix, that changes which source feeds your outbound calling queue specifically. It doesn't automatically mean you should switch your entire enrichment stack over to that vendor, since email deliverability and firmographic accuracy are separate questions worth testing on their own terms.

Decide in advance what gap would change your decision, before the first call goes out. If the difference between vendors sits inside the noise you would expect from your sample, treat them as equal and choose on price and other features. If one vendor clearly connects more often, move its numbers to the front of the calling queue and leave the rest of the stack alone. For example, a vendor that wins on phone connects but lags on email deliverability should feed your dialer while another source feeds your email sequences. Each source earns its role on the metric it actually wins, not on a single overall verdict.

A clean connect-rate result only tells you the number was reachable. It says nothing about whether the account was worth reaching in the first place, and it's easy to mistake a strong test result for a strong data vendor overall when it's really only strong on this one dimension. Run the same kind of test again after any major re-platforming on the vendor's side, and don't assume a result from six months ago still holds, since phone data ages differently than email or firmographic data and can shift meaningfully after a vendor changes how it sources numbers. Keep the raw call logs from each test round too, not just the summary connect rate, since a future dispute over methodology is much easier to settle with the original data in hand than with a remembered conclusion.