there are two ways people fail at cold email.

the first: send a few hundred emails, don't get replies, decide cold email doesn't work, and quit.

the second: change five things at once, see a bump in replies, have absolutely no idea which change caused it, and then can't replicate it.

both come down to the same mistake. not enough volume and not enough discipline with variables.

THE ONE-VARIABLE RULE

change the offer, the subject line, OR the CTA. never more than one at a time.

if you change your subject line AND your CTA AND your opening line all at once and your reply rate doubles, which one did it? you genuinely have no idea. and you can't build a repeatable system on "i genuinely have no idea."

run each test for long enough to get a real signal. a handful of sends tells you nothing.

WHAT TO ACTUALLY MEASURE

• Reply rate: how many people responded (positive or negative)
• Positive interest rate: how many responses were actually interested
• Booked calls: how many turned into real conversations

open rate is NOT on this list. open rates are unreliable and tell you almost nothing about whether your emails are actually working.

THE RULE OF 100

100 contacts per day. 100 days minimum. before you draw ANY conclusions about whether cold email works for your business.

that's 10,000 emails before you're allowed to say "this doesn't work."

volume hygiene matters too. 10-15 sends per inbox maximum to keep your deliverability healthy. spread your volume across multiple inboxes instead of hammering one.

A/B TEST TRACKER

fill this in religiously. every test gets logged. every result gets recorded. if you're not tracking it, you're guessing. and guessing at scale is just burning money faster.