Negative keyword lists was launched just over a week ago and likely not noticed by many AdWords users was an improved platform for controlling and refining campaigns by using large lists of negative keywords. The main benefit is that agencies, franchises or consultants can now develop reusable core lists of negative keywords that might be specific to their industry, type of client or geographic location in the world. It is even possible to have a standard set of keywords that you include due to their very low conversion rates in previous campaigns or know to generate extremely high search volume and associate that list with multiple client campaigns
WordStream has announced that they’ll be offering a free negative keyword tool .