I don't mean to downplay the effort of interaction-type tasks. It's the result of observing people around me. I know many people who are happily productive on sales for 12h workdays. I know no developer who's proud of code written on the 12th hour.
Don't assume that these sales people are so happy to work overtime. They probably rely on commission and/or need to hit that sales target. Sales teams are known for super-competitive, target-driven, and high-pressure culture. We software engineers have it easy in comparison.
