Spiraclean, you nailed it when you said "something tells me Dyson can easily afford it given the almost unlimited resources they seem to lavish on their R&D fetish". The point is, without demonstrators, they could reduce the retail prices or increase profits. They choose instead to pump it into employing demonstrators. Now, I am all for giving people jobs, of course I am, but having been in business myself, profits are my first and final thought in anything.
Adam, you are the perfect gentleman to ask, how many more sales of Dyson cleaners is your store making solely as a result of the demonstrator being in-store at the weekends? From what I know, it would be very hard to ascertain a figure, and assuming as a store you don't know, I cannot see how Dyson would know. Not only this, not all customers who the demonstrator meets will make a purchase that day; some will return in the week or buy from other outlets. That again is a figure which cannot be measured. Also, do you ever get Dyson and other vacuum demonstrators in-store on the same day? If so, how does that go down?
Considering all the money Dyson spend in total, countrywide, each weekend, I am amazed that the demonstrators are given no budget to allow a customer a small cash-back incentive for purchasing "on the day", or, at the very least, a few freebies, such as optional tools, which must actually cost Dyson very little to make.
Their demonstrator program proves that almost anything is possible if one has that budget to do so, whether it "hits the spot" is another matter. If profits are of concern to Dyson, then I can see how this program works.