How does Baidu do differently in providing organic search result?

Baidu (the largest search engine company in China) was criticized heavily several years ago because at that time, Baidu was very active in promoting its advertisement service. Baidu seemed combine advertisements with organic search results together. It was not clear to the user, on its search result page, which portion of the results was appeared because of paid advertisement and which portion was the organic results. As we all know, when people search in Google, the results appear below the search bar is what called the organic results, which are the most popular pages related to the key words. Normally, there will be no advertisement appear at this place. But Baidu did differently.

Because of this strategy, Baidu faced a lot criticism from the public for its misleading. So Baidu changed gradually, and now a days, you could clearly find out which results are for advertisement. It is important for search company to insist on the ethical issues because the search algorithm is not apparent to individual users and is easy for search company to manipulate the search result to help its advertisement service.