This is not really an answer, but it depends how you define 'product market'. I am too lazy to look it up. I think it means retail goods. A retail good is not a 'factor of production'. A 'factor of production' is a thing that is used in producing other things, more commonly and specifically (as noted above) land, labor and capital goods.
There is of course a gray line. For example, a rock might be factor of production to a cement plant, if ground accordingly, but it might be sold in Home Depot to consumers who put them in their gardens.