1. A system permitting a commercial advertiser with retail stores to place video or still-image advertisements at selected times and locations on a network of multiple electronic roadside displays, and to tie the roadside advertisements into point of purchase displays at the advertiser's retail stores, said system comprising: a network including a plurality of roadside electronic displays; means permitting a commercial advertiser with retail stores to place video or still-image advertisements at selected times on selected ones of the network's roadside electronic displays; and point of purchase displays at selected ones of the commercial advertiser's retail stores displaying content that ties into the content of the video or still-image advertisements run on the roadside electronic displays.