Usually the work sample is something simple that doesn't take longer than a day or two. Many interviews that don't do work samples can go on longer than that and accomplish nothing. I was hired after doing a work sample that took a day. I was still paid for my work, irregardless of being hired. The work sample wasn't "standardized", just a typical task one of the other developers would have done otherwise. So I would encourage any employers reading to try this process out--it's better for both parties.