Normally, one thinks of advertising as part and parcel of any business enterprise. But, it is amazing how many businesses, even those that cater to the general public, do absolute no advertising via television, radio, daily newspapers (other than classified advertisements), or billboards.
This isn't just a matter of businesses that are primarily in the business to business market. Only a modest percentage of liquor stores adverise. Few law firms advertise, even when they practice primarily in areas like estate planning, family law, criminal law and personal injury law that serve mostly households in the general public. Almost no accountants who serve mostly individuals, or medical practices advertise to the general public. Relatively few restaurants do.
Likewise, many quite large businesses in the business to business market don't advertise. When was the last time you saw a TV spot for Delphi (a Fortune 500 automobile parts supplier)?
One of the little wonders of modern capitalism is the complex web of non-advertising marketing means by which all of these businesses, my own and that of almost all of my clients included, generate business sufficient to keep themselves going.