1. A system to detect and maintain retail store promotional price tags comprising: a heuristic promotional price tag description extractor module adapted to extract heuristic descriptions of promotional price tags; a heuristic rule deriver module in communication with the heuristic promotional price tag description extractor module, the heuristic rule deriver module being adapted to derive a set of promotional price tag parameters; a store shelf image acquisition system adapted to acquire shelf images in a retail store; a barcode locator and recognizer module in communication with the store shelf image acquisition system, the barcode locator and recognizer module being adapted to analyze images acquired by the store shelf image acquisition system to localize barcodes; and a heuristic promotional price tag classifier module in communication with the barcode locator and recognizer module and the heuristic rule deriver module, the heuristic promotional price tag description classifier module being adapted to extract heuristic attributes from the images acquired by the store shelf image acquisition system using the set of promotional price tag parameters supplied by the heuristic rule deriver module.