Abstract: An influence tracking system may track influence on multimedia content selections. A popularity prediction identification system may identify sources that accurately predict the popularity of a product or service. A recommendation system may recommend products or services of a particular type.

Abstract: Copper sulfide in the presence or absence of metallic copper contained in a dross obtained from the copper drossing of lead bullion is separated from metallic lead entrained or occluded in the dross by introducing the dross into a vessel other than a reverberatory furnace, usually a kettle, also introducing an alkali metal sulfide, preferably sodium sulfide, into the kettle, and heating the dross and alkali metal sulfide together in the kettle at an elevated temperature not in excess of 1200.degree. F. and for a time sufficient to melt together the dross and alkali metal sulfide. The thus-obtained molten dross releases the entrained molten lead which falls to the bottom of the kettle.