Double-Check Your ROI Reports
This recommendation is primarily for marketers who use a third-party solution, or several, plus their own internal sales data. One agency I worked for ran both external and internal reporting systems for paid listings. When our data showed a 30% discrepancy in orders from what the third-party vendor was reporting, we knew there was a problem. This story points out a sad reality: Data from different reporting systems almost never matches. I've experienced this when comparing search engine click-through reports to web traffic analytics reports, and even two web analytics reports from competing vendors.
What's an acceptable reporting discrepancy number? A couple of industry experts agree that up to a 10% discrepancy is normal. That's probably because on the web, tools count in myriad ways, and don't count or double count site visitors and associated sales.
Both deep data tracking and routine campaign analysis assist with this issue. You'll be able to catch anomalies in discrepancy patterns. Perhaps your internal sales report and third-party ROI report are consistently off by 57%, but suddenly you notice a 10% incongruity. The random fluctuation suggests an error with what's being, or not being, counted.
In his book E-Commerce User Experience, Jakob Nielsen gives several examples of why people put items in a shopping cart but don't buy at that time. Consumers might use the shopping cart to find out how much they'll have to pay, or leave the site to comparison shop. Their browser may crash during the transaction, or perhaps shoppers are interrupted.