Before the fame: Pam Dawber for Prell (1973)

 Procter & Gamble doesn't make Prell shampoo anymore---it was sold off to a smaller company---but in the 70's, they used a gimmick where the ads would end with a pearl being dropped into a bottle of the product.

One such example is this item from approximately 1973 with a pre-Mork & Mindy Pam Dawber.

Quaint.