I used to work in a job that paid me twice as much as what I'm doing now. And we all ran to pick up groceries, mail a letter, or go to the bank (only the employees that banked at the only branch close to our job). So I would say yes, people do run errands while they're at work. It was the trade off we got for not having regularly scheduled coffee breaks. We could just do some of these things when we weren't busy.