Our product is a financial website, similar to an online banking site. We conduct low-cost usability tests in the spirit of what Steve Krug describes in "Rocket Surgery Made Easy."
We recruit most of our participants from Craigslist. They are not current users. (In fact, before I recruited them, they had never heard of us.) Sometimes I wonder whether they interact with the site the same way they would if they were dealing with their own money (rather than running through some pretend scenarios in which they may not have any emotional involvement).
Has anyone else run into that issue? Did you decide it was a real problem? If so, did you try anything to compensate for it?