Keeping an eye on national retail trends is made much easier with a subscription to the excellent RetailCustomerExperience.com, who graces us this morning with an eye-opening piece on the dangers of misinformation lurking in various retail traffic measurement techniques.
Measuring retail traffic is done because there’s a strong correlation between retail traffic and sales – more traffic often (but not always) means more sales. But getting accurate reads of traffic is a technical problem that various sources of numbers tackle in very different ways.
Getting at the bottom of the problem, Mark Ryski at RetailCustomerExperience takes a closer look at three holiday 2014 reports. “Why You Should Take Retail Traffic Indexes With A Grain Of Salt” shows the widely varying results of widely varying data collection and preparation techniques — and suggests that even with numbers about shoppers, caveat emptor — let the buyer beware — still rules the day.
Part of the challenge is in understanding exactly where and how each of these companies is measuring store traffic. The ShopperTrak data, according to the WSJ article, is based on 60,000 malls and large retailers across the country, but in fact, according to ShopperTrak’s own website, the company analyzes data from over 60,000 locations across 90 countries and territories. How many of these stores are in the US, and which ones were included in the index? It’s also reasonable to know if any particular retail categories were over or under represented. For example, if an index is primarily comprised of specialty apparel retailers, then how representative is it of the entire retail industry?
RetailNext bases its results on 34.6 million shopping trips. The company doesn’t define what a “shopping trip” is; however, it does say that it collects data from 65,000 sensors in retail stores.
It’s not clear how many unique stores are represented by the 34.6 million counts, but it’s a relevant question. For example, if these 34.6 million counts were captured only from large stores that had average daily traffic of, say, 1,000 traffic counts per day during the November-December holiday period, we would conclude that the index is based on only about 600 unique stores.
If, however, the index included only small stores that had averaged only 100 counts per day, the 34.6 million counts would represent about 6,000 unique locations. It’s important to understand how many unique stores are included in an index because the number reflects market coverage — if an index has insufficient coverage or is not based on a statistically significant and representative sample of the market, how valid will the results be?