NEW YORK (AdAge.com) -- The changes which are about to rumble through the nation's out-of-home advertising business are among the biggest its seen in 75 years. That's according to Joe Philport, CEO of the industry's Traffic Audit Bureau. In February, the TAB rolls out a revolutionary new currency and value system for the buying and selling of out-of-home ad space. That system is also the pivot on which the industry hopes to dramatically -- and more profitably -- reinvent its relationship with ad agencies and big marketers.