The deal means that whenever users install RealPlayer, they will be given the option to also install either the Google Toolbar or Firefox. The distribution agreement will soon be extended to include downloads of Real's Rhapsody music service and RealArcade games. Real Networks said it "regularly distributes" more than 2m items of software a day worldwide.
Google was already in a deal with Real, and this is partly an extension of that. How or why Real benefits from this at a customer perspective is unknown, but likely a partnership of this nature can't hurt them.