Purchasing decisions by buyers are probably not based on whether or not the seller produces pottery for a living. I'd wager price, convenience (fast shipping, etc.), size, and design matter far more to a buyer.
Here's how the mugs were selected:
> The five mugs chosen for this study were selected because they were found to contain lead in a screening-level assessment. Specifically, 24 mugs from the authors’ office were tested using an Olympus Innov-X Delta handheld X-Ray fluorescent (XRF) analyzer. Each mug was measured once with the XRF gun at its highest sensitivity setting, which required the tester to hold the analyzer over the mug for 45 s. The three mugs with the highest resulting lead concentrations (1,223 to 7,034 mg/kg) were selected for the present study. These mugs each had decorative elements and will be referred to by their predominant colors: Green Decorative, Yellow Decorative, and Red Decorative. In addition, two representative mugs were selected from the batch of office mugs baring the authors' company’s logo. These will be referred to as Black Logo1 and Black Logo2. All five mugs selected were in active use in the authors’ San Francisco, California, office environment, and were typically washed daily in an automatic dish washer. Four of the five mugs were purchased in the U.S., and one was purchased in Europe (Red Decorative). The mugs all appeared to be in good condition, with no obvious signs of damage or wear.
The types of mugs found in a standard office probably match the types of mugs many people have in their homes. Regardless, lots of coffee is regularly consumed in an office environment.
I believe the results of this study are a little more relevant than your comment suggests.