It was revealed that NHN has sent several threatening emails to its advertisers saying, "If you do not stop providing ads to a certain memo application maker, your ads will be deleted in Naver".

After witnessing an app that allows users to stick memo on any webpage and that may lead to damaging Naver's ad revenues, the company took full advantage of its position, where its keyword market share is up to 75%, to threaten its advertisers.

On July 10, a service provider of memo platform app 'MemoThis', Isforu, revealed that NHN's affiliate search platform operator NHN Business Platform (or NBP) has sent an email to its advertisers back in November 2011 and January 2012, saying, "If you do not stop distributing MemoThis and providing Advertising • Events •  Product information, we will block your ad postings on Naver and exposure of the search."

Image of NBP's email sent to its advertisers on January 2012

Based on Naver's terms of agreement, NBP claimed that 'MemoThis' had a negative impact on its advertising sales and that it is adware, a type of malicious software that presents unwanted advertisements to the user.

However, the agreement says that the advertiser should not interfere with company's business, and there is no specific standard of adware. Besides, MemoThis is the government-funded next generation memory platform which is created as "social layer", that has been selected as one of government's R&D technology innovation project in 2009.

More than 10 advertisers stopped displaying ads on MemoThis in November 2011 after receiving a warning email, worrying that NBP could block their ads. It's because their sales can suffer if their product exposure decreases.

The advertisers include LG Fashion, Dongwon F&B, ILDONG FOODIS, Boryeong, Namyang Dairy Products, Hi-Mart, TourBaksa, and others. These companies were putting ads on MemoThis and distributing MemoThis on their own websites to maximize their ad exposure.

On January 2012, Isforu submitted a certificate claiming that MemoThis is a legitimate software that is provided under the agreement of users and advertisers.

However, Isforu received an official letter from NBP saying, "MemoThis is hampering the company's advertising sales" which was after four months, when all the ads on MemoThis were gone.

Isforu is planning to take legal actions based on NBP's official letter and threatening emails sent to advertisers.

Isforu Representative Choi Moon-Sung pointed out, "MemoThis has been recognized for technical excellence and funded by government but NBP regarded its business as an act of illegal software distribution. Threatening advertisers to interfere the installing of MemoThis based on its market dominating position is business interruption and unfair trade practices."

Kim Jung-Woo, a rep from NHN said, "It was done due to raise the quality of Naver's keyword searching and the exposure of advertising. A portal operator is obliged to protect users and advertisers."

NBP's official letter NBP sent to Isforu in May 2012