I happened to search for "temporary staffing" on youtube.com and noted that one staffing firm in particular has made very good use of that venue. Frontline Source Group dominates both in terms of number of videos uploaded and in terms of hits.
We live more and more in the age of moving pictures--the number of hours per day that people spend on TV and internet video (the two of which are gradually merging in any case) greatly dwarfs old-fashioned reading, and is even, sadly enough, cutting into the time people spend with other people.
It may be early to launch into youtube in a big way, but it's something to keep on the radar screen. The two Frontline Source Group videos linked above have generated nearly 50,000 hits each.