From that site:

Most Americans who watched TV in the 50's have fond memories of the Indian Head Test Pattern. This makes perfect sense. During the early years, viewers saw this image (and others like it) more often than they saw actual programs!

In the beginning, TV stations operated in the evening only. By the late 50's, many had expanded their offerings to 20 hours per day. Even so, there was still quite a lot of dead air. Test patterns (or test cards, as they were called in England) served many purposes: they gave studio technicians and home viewers an image to focus on while they adjusted their equipment, and they gave people something to look at while they were waiting for their favorite station to sign on each day.



I've told this story before but its worth repeating.

Partly because my dad had pinball machines and juke boxes in bars he got in on the ground floor of tv then (he installed them in many bars back in the late 40's/early 50's). We were one of the first families in the neighborhood to actually have a tv, and back then there were four channels in New York. They usually started their broadcast day about 7:00 a.m. and ran through about midnight (the test pattern would show at all other hours).

Well, my mom used to do her ironing at night while she waited for my dad to come home. She'd watch tv while ironing. One night she got angry that nothing was on, so she called up the tv station and complained to them that her husband bought a new tv and they weren't showing anything. My mom used to live for moments like this, and within a few minutes they actually put a movie on for her!!

She's too old now to remember what movie they aired but she remembers the event.