Read the article: https://thecorrespondent.com/100/the-new-dot-com-bubble-is-here-its-called-online-advertising/13228924500-22d5fd24 and answer the following:

1) Why do you think the advertisers/big companies keep advertising even when the experiments show that advertising dollars are not as effective? Describe the principal agent problem in the context of advertising and advertising industry. How did the article address this concept?

2) What did eBay learn with their experiment on search advertising? Why do you think they got those results? (note: the original academic article that describes the eBay experiment is here: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2444538).