Soap Operas?

Some minutes ago I was happy to learn where the name "soap opera" comes. I will explain.

The last days I fell in love with Audi R8. to get some up-to-date info, I consulted -what else- Wikipedia. There I found out that this supercar is based on the Audi Le Mans quattro concept car, which was based on the earlier Audi RSQ concept vehicle. The latter was specially designed for the movie 'I, Robot' as a 'product placement'. But what was a product placement? Ok, it is something intuitive, but I wanted to learn a bit more. So again in Wikipedia I read its definition, as well as the origins of this way of marketing:
"In early media, e.g. radio in the 1930s and 1940s and early TV in the 1950s, programs were often underwritten by companies. "Soap operas" are called such because they were initially underwritten by consumer packaged goods companies such as P&G or Unilever."

Interesting, right? :)