Understanding the efficiency of keywords in search engine marketing - a comparison study using data envelopment analysis

摘要

We use data envelopment analysis to examine and compare the pricing efficiency of keywords in Google and Bing sponsored search markets. It is found that keyword efficiency scores are not significantly different between Google and Bing search markets. We also evaluate the effectiveness of the Google Adgroup recommendation system that suggests the keywords in a campaign being grouped by each of the apparel attributes: generic, fabric, sex, price promotion, colour, and size. Efficiency scores significantly vary across the Adgroups categorised via Google's recommendations. Size and colour related key phrases are more efficient than generic and promotion/sale related keywords. When comparing efficiency by match type, broad terms are more efficient than modified broad terms. In addition, 'efficiency scores' and Google's 'quality scores' for keywords are found positively correlated. High-efficiency keywords are found generating high revenue for advertisers, while quality scores are found only significantly related to cost.