I think the multiple clips was also intended to frustrate the surfer provoking him to buy.
As far as format I am a firm believer in letting them sample the format for which they are buying.
If you have wmv in the members area, i feel it's a good idea to have them on your gallery, so the customer knows and is sampling exactly what he is going to purchase. (thus eliminating any surprises resulting in a dissatisfied customer)
like so: (been doing one clip since April 2007)
http://www.beachmodel.com/free_galle...p?ccbill=XXXXX
http://www.beachmodel.com/free_galle...p?ccbill=XXXXX
However, in order to keep all affiliates happy I also do some flash galleries with one long clip & pics to hopefully make everyone happy:
http://www.beachmodel.com/free_galle...p?ccbill=XXXXX
http://www.beachmodel.com/free_galle...p?ccbill=XXXXX