A "complementary good" is a product that is often consumed alongside another product. For example, popcorn is a complementary good to a movie, while a travel pillow is a complementary good for a long plane journey. When the popularity of one product increases, the sales of its complementary good also increase. By producing goods that complement other products that are already (or about to be) popular, you can ensure a steady stream of demand for your product. Some products enjoy perfect complementary status—they have to be consumed together, such as a lamp and a lightbulb. However, do not assume that a product is perfectly complementary, as customers may not be completely locked in to the product. For example, although motorists may seem required to purchase gasoline to run their cars, they can switch to electric cars.

It's not news to anyone that we judge others based on their clothes. In general, studies that investigate these judgments find that people prefer clothing that matches expectations—surgeons in scrubs, little boys in blue—with one notable exception. A series of studies published in an article in June 2014 in the Journal of Consumer Research explored observers' reactions to people who broke established norms only slightly. In one scenario, a man at a black-tie affair was viewed as having higher status and competence when wearing a red bow tie. The researchers also found that valuing uniqueness increased audience members' ratings of the status and competence of a professor who wore red sneakers while giving a lecture. The results suggest that people judge these slight deviations from the norm as positive because they suggest that the individual is powerful enough to risk the social costs of such behaviors. A series of studies show that people view an individual positively when the individual only slightly challenges the norm for what people should wear.

Claims that local food production cut greenhouse gas emissions by reducing the burning of transportation fuel are usually not well founded. Transport is the source of only 11 percent of greenhouse gas emissions within the food sector, so reducing the distance that food travels after it leaves the farm is far less important than reducing wasteful energy use on the farm. Food coming from a distance can actually be better for the climate, depending on how it was grown. For example, field-grown tomatoes shipped from Mexico in the winter months will have a smaller carbon footprint than local winter tomatoes grown in a greenhouse. In the United Kingdom, lamb meat that travels 11,000 miles from New Zealand generates only one-quarter the carbon emissions per pound compared to British lamb because farmers in the United Kingdom raise their animals on feed (which must be produced using fossil fuels) rather than on clover pastureland.↵
When food does travel, what matters most is not the distance traveled but the travel mode (surface versus air), and most of all the load size. Bulk loads of food can travel halfway around the world by ocean freight with a smaller carbon footprint, per pound delivered, than foods traveling just a short distance but in much smaller loads. For example, 18-wheelers carry much larger loads than pickup trucks so they can move food 100 times as far while burning only one-third as much gas per pound of food delivered.