How to test a new lead supplier without risking the quarter

Buyers test new suppliers constantly and learn less than they should, because the test is usually designed to be cheap rather than to be conclusive. Twenty leads over three weeks, handled by whoever was free, judged on whether it 'felt' better. That produces an opinion, not an answer.

1 Size the test around appointments, not leads

The number you are really trying to measure is conversion, and conversion is rare. If you convert around one lead in twenty, a twenty-lead test can easily produce zero jobs from a perfectly good source, or one job from a poor one.

Work backwards from appointments instead, because they happen roughly five to ten times more often than sales and therefore stabilise much faster.

Most trials should be sized for the middle row. If you cannot afford a hundred leads to make the decision, run the test over a longer period rather than shrinking it.

2 Hold everything else still

A test only isolates the supplier if nothing else changes at the same time.

• Same salespeople, or an even split across the same team
• Same call cadence and script
• Same postcodes
• Same weeks, running in parallel with your existing source rather than after it
• Same CRM process, with the source recorded on every record

3 What to read early, and what to wait for

Some signals are trustworthy within days. Others are noise until the volume arrives.

4 The questions to ask at the end

• Did the leads contain what we were told they would contain?
• How many attempts did contact take, compared with our existing source?
• What did the replacement process feel like when we used it?
• Did the supplier tell us about a problem before we noticed it?

That last one is worth more than it sounds. Any supplier will handle a good month well. How they behave in a bad week is the thing you are actually buying, and a trial is the only cheap opportunity you will get to see it.

5 A sensible first test

A hundred leads, one vertical, your best-covered postcodes, split evenly across the same two salespeople who handle your current source, run over four to six weeks alongside what you already buy. Record source on every record. Judge on appointments per hundred leads and on how the supplier behaved, and leave close rate for the second round.