Pay-per-click search is the largest single line in many web marketing budgets. To ensure your campaigns are healthy, you should conduct a PPC audit about every six months. A PPC audit has four components:

• a PPC sales and order audit (discussed last week),
• a cost data audit (today’s topic),
• a bid audit, and
• a marketing performance audit.

These four steps aren’t as much work as they sound — with the data in hand, all four components combined might take an afternoon to complete.

Today we’ll discuss how to do a PPC cost data audit.

The idea here is so incredibly basic — namely, make sure the cost data in your PPC search reports are accurate — that you might dismiss this as a needless check. However, you’d be suprised by how often tools or agencies report incorrect cost data. If you don’t have accurate cost data, you can’t run your campaigns correctly.

Here’s the process:

1. Pick a recent calendar month.
2. Ask your accounting department (if you’re paying your media bills) or your SEM (if they are) for actual advertising costs paid for that month to each major search engine (Google, Yahoo, MSN, Ask, etc). The accounting folks should pull these costs from the actual advertising invoices received from the engines (if you pay by invoice) or from the actual credit card statements (if you pay by credit card). Check the totals match the invoices.
3. Next, pull cost data for the same period for each engine by day from the engines themselves. Log in to the engine’s web management interfaces, or ask your agency to generate those reports.
4. Finally, gather cost data from your weekly search performance reports provided by your agency, your search management tool, or your in-house team.
5. Then, for each engine, in aggregate and by day, compare these three sets of cost data — costs as invoiced by the engines, costs as reported by the engines, and costs as reported by your search performance reports.
6. These three sets of cost data should match. Due to rounding, credit card timing issues, timezone issues, click makegoods, etc. “match” here means “the same to within a few percent.”
7. If the three sets of costs match up, in aggregate by engine and by day, congratulations. Roll ahead to the bid audit.
8. If they don’t, roll up your sleeves and start digging in to see why.

Next up in this series: auditing your PPC bidding technology.

All posts in the PPC Audit series:

1. PPC Cost Audit
2. PPC paid search Sales Audit
3. PPC paid search Bidding Audit
4. PPC paid search Marketing Audit