1. A system for synchronizing broadcast advertising inventory data between a broadcast vendor system and a media buyer's media resource planning system comprising: a) a computer server adapted to receive original and revised packages of advertising inventory data from the broadcast vendor system and transmit original and revised packages of advertising inventory data to and receive advertising inventory data from the media buyer's resource planning system, said original and revised packages of advertising inventory data including a header, program, week, cost, network serial number, advertising units and product code; b) a computer memory storage device in communication with the computer server and upon which is stored a database storing packages of advertising inventory data received by the computer server from the broadcast vendor system and the media buyer's resource planning system; c) said server also adapted to: i. receive headers including technical parameters of packages of advertising inventory data from the media buyer's resource planning system and the broadcast vendor system; and ii. store the headers on the computer memory storage device; d) a matching application stored on a computer in communication with the database that performs a comparison between: i. a header received from the media buyer's resource planning system and stored in the computer memory storage device and a header received from the broadcast vendor system; and a multi-tier comparison between: ii. an original package of advertising inventory data and a revised package of advertising inventory data; said matching application assigning a tier as a result of the multi-tier comparison based on the following: A) tier 1 if exact match by network serial number, program, week, cost and advertising units; B) tier 2 if match by program, week, cost and advertising units; C) tier 3 if match by week, cost and advertising units; D) tier 4 if match by program, cost and advertising units; E) tier 5 if match by program, week and advertising units; F) tier 6 if match by cost and advertising units; G) tier 7 if match by program and week; and H) tier 8 if none of network serial number, program, week, cost, advertising units and product code match; e) an analysis application stored on a computer in communication with the matching application and the database that enables a user to: i. review results of the comparison between the header received from the media buyer's resource planning system and stored in the computer memory storage device and the header received from the broadcast vendor system; ii. approve a package corresponding to the header received from the broadcast vendor system, designate the approved package as an original package and transmit the approved package to the media buyer's resource planning system for designating a product for the approved package; and iii. review results of the multi-tier comparison of the original package of advertising inventory data and the revised package of advertising inventory data performed by the matching application, including a comparison of headers of the original and revised packages of advertising inventory data, and direct uploading of the revised package of advertising data from the database to the media buyer's resource planning system.