You had to be there.

Up until that point, Pong came baked into coin-op cabinets or standalone TV console units.

Apple's Pong game came on an audiotape cassette in BASIC source form. You could play the game and modify the source if you wanted. You could even save your modified work to a cassette and give it to someone else.

That was an insanely powerful idea at that time. A TV ad like this obviously doesn't have time to explain it all, but the statement was very correct and very compelling to those that knew what it meant. Apple sold millions of units on this idea.

Writing your own video game was the hook that got me tinkering with the ][, bless it's little beige-boxed heart, and I have my whole career to thank because of it.