The first advertisement for VisiCalc appeared in the May 1979 issue of Byte Magazine. Here is the cover:

Byte May 1979

Dan Fylstra, head of our publisher Personal Software and one of the founding editors of Byte Magazine years before, decided to take out a brash teaser ad in the back section. VisiCalc was unannounced at the time, and not scheduled to ship for a while. I thought he was being a little strong, but he really was right on target for many people (accountants, business planners, etc.):

First VisiCalc ad