Instruct: Classify an Amazon review into positive or negative sentiment.
Query: In 1970 Jim Mullen founded an ad agency. This is what he learned.

A lot of the guys who write books telling you how to be great are guys who are in the business of telling you how to be great, and their credentials are primarily that they've been telling people how to be great for years, both privately as consultants and publicly in books and lectures.And while I would not dream of denigrating them or their experience, when someone who has built a successful advertising agency from scratch decides to set down his thoughts on the topic, there is a different kind of gravitas in the telling, an added legitimacy that demands that you stop and pay attention.Jim Mullen founded the ad agency that bears his name in Boston in 1970 and since then it has grown into one of the most well-respected - (to read the rest of this review, please visit theagencyreview.wordpress.com)