Pondering Blondie

Back on the 16th there was a particular Blondie strip that got me wondering about Dagwood and what it is that he actually does.

Here Dithers assigns him a "major account" and which Dagwood must come up with a "proposal" in order to secure this "account". These all sound like sort of vaguely businessy things, but  what does it actually mean? What does this company actually do?

Today the mystery deepened when it was revealed that Dagwood is actually the office manager.

I'm confused. Why would the office manager be asked to "nab" new accounts? Is an office manager not what I think it is? And what does this company do? Does anyone know?