The contextual search technology is invented by Google and followed by BBHI. The leading companies such as Google and BBHI show clear competitive edge in technology, data accumulation, algorithm maturity etc. The core task of BBHI's contextual search technology is to "calculate" the "key words" in each target webpage analysis, so that Yahoo! Inc can search and match the proper advertising information from its ad inventory. Based on the CTR (click-through rate) and RPM (revenue per mille) of the advertisement in each strategy expectation, BBHI uses the more refined algorithm to guarantee the precision of key words, matches the best advertisement accurately and outperforms the competitors.