Measuring cost per call

Four formulas, from loose to strict

Each formula answers a different question. Use them in order, since each one needs more data than the last.

VereTel’s desk gives you the first two: calls per tracking number, and answered versus missed. Qualified calls and policies come from your own records. The desk is a read-only log, so keep those counts in the system you already use. See the cost per call entry.

A worked example, with hypothetical numbers

Suppose an agency spends $2,000 in a month on one search campaign, with its own tracking number.

• The number receives 80 calls: cost per call is $25 ($2,000 ÷ 80).
• Of those, 64 were answered and 16 were missed: cost per answered call is $31.25 ($2,000 ÷ 64).
• Staff judge 40 of the answered calls to be real prospects: cost per qualified call is $50.
• Eight became policies: cost per policy is $250.

Note the gap between $25 and $250. A source that looks cheap per call can be expensive per policy, and the other way round. The missed calls are the easiest gap to close: answering 12 of the 16 would have added 12 conversations for no extra spend.

Set the number against what a policy is worth to you. The ROI calculator takes your own inputs.

Pitfalls that distort the numbers

• Duplicate calls. One person may call three times in a day. Counting all three inflates your call count and flatters cost per call. Look for repeated caller numbers on the call list and decide how you count them, then keep to that rule.
• Short calls. Wrong numbers, hang-ups and pocket dials are logged like any call. Look at duration. Google’s call conversions use a minimum call length for the same reason. Pick a threshold that fits your product and apply it consistently.
• Missed calls. A missed call is spend with no conversation. Do not drop missed calls from the denominator when you calculate cost per call; report them as their own number, and work to lower them.
• Shared numbers. If two campaigns use one number, their calls cannot be separated and neither cost is real. See attributing calls to ad clicks.
• Lag. A call in October may become a policy in December. Compare like with like by measuring policies against the calls of the same period, or wait until the cycle is done.
• Last-touch bias. A phone call credits the source dialed, which may not be the first ad the person saw.

A routine that keeps it honest

1. Every week, export or copy the call counts per tracking number for the same date range as your spend.
2. Note answered, missed and any repeat callers.
3. Add qualified calls and policies from your own records when you have them.
4. Compute all four measures per source in one sheet, using the same formulas every time.
5. Change one thing at a time and give it a full cycle before you judge it.

VereTel does not export data or produce reports today, so this sheet is manual. A week of calls is short enough to do by hand. If you want to see how numbers and sources map, read what is call tracking.