Toothpaste: we all use it (hopefully) at least twice a day.
Toothpaste is big business. The global toothpaste market in 2015 was estimated at US$12.6 Billion. That’s similar to GDPs of countries such as Albania, Mozambique and Burkina Faso.
Promoting toothpaste is big business as well. Annually P&G spends $192 million on advertising for Crest alone in the USA.
Dentists and other dental professionals promote and encourage people to use toothpaste (sometimes a particular brand and not entirely for free).