I used to work at an engineering firm and one day I saw one of the engineers leave at like 2pm on a Wednesday and he was like, "Bye, see you next week!" He had been busting his ass to finish a project and already hit his 40hrs for the week.
I was a temp at the time but needless to say, I jumped at the chance when they offered me a real job.
In BTVS they can. There's a vampire who's cursed with having a soul and is therefore unwilling to hurt humans, so he just toddles down to the butcher and gets blood from them.
Soulless vampires either like the hunt or just prefer the taste of human blood. For instance, some vampires just raid blood banks instead of hunting humans.