The offline tracking scans most credit and debit card transactions to help Google automatically inform merchants when their digital ads translate into sales at a brick-and-mortar store. Google is also introducing several other features designed to help merchants drive more traffic to their physical stores and to gain a better understanding on how digital ads appearing across a variety of devices are affecting their sales. In the case of the store sales measure tool, Google's computers are connecting the dots between what people look at after clicking on an online ad and then what they purchase with their credit and debit cards. Google says its computers can collect identifying data triggered by online clicks and match it with other identifying information compiled by merchants and the issuers of credit and debit cards to figure out when a digital ad contributes to an offline purchase.