As newspapers try to invent a digital version of weekly advertising inserts, Google is launching a service Tuesday that could beat them to the punch. Google will create Web-based circulars for major retailers such as Best Buy and Macy's. Text ads appearing in Google Search results will send readers to circular-style ads with pictures of multiple products and large type. This is potentially bad news for newspapers, which have held on to revenue from weekly ad inserts after losing much of the classified business to the Internet. A bit of short-term good news: Bloomberg reports that Google will buy some print ads to promote its new digital circulars. || Earlier: AP, newspapers to redeem their share of coupon business with mobile app iCircular