Sentence:  But the real way to build a successful online business is to be better than your rivals at undermining people's control of their own attention. Partly, this is a result of how online <WSD>advertising</WSD> has traditionally worked: advertisers pay for clicks, and a click is a click, however it's obtained. 
Meaning of the word marked with <WSD> tags:  Communication whose purpose is to influence potential customers about products and services.