Can someone explain to me the distinction between the "Product Collection" subtheme (http://www.brickset.com/search/?subtheme=Product%20Collection
) and the "Virtual Product Collection" subtheme (brickset.com/search/?subtheme=Virtual%20Product%20Collection
)? The later seems to have made a new appearance in 2012. They both seem to be collections of other sets but only one of the two (I'm not sure which one since I actually have two entries in each category) is being included in the My Sets count while the other is not.