Paley changed broadcasting's business model not only by developing successful and lucrative broadcast programming but also by viewing advertisers and sponsors as the most significant element of the broadcasting equation. Paley provided network programming to affiliate stations at a nominal cost, thereby ensuring the widest possible distribution for both the programming and the advertising. The advertisers then became the network's primary clients and, because of the wider distribution brought by the growing network, Paley was able to charge more for the ad time. Affiliates were required to carry programming offered by the network for part of the broadcast day, receiving a portion of the network's fees from advertising revenue. At other times in the broadcast day, affiliates were free to offer local programming and sell advertising time locally.