In early May, stocks of Gree and DeNA fell more than 20% after the nation's Consumer Affairs Agency said it was considering whether a sales method called "complete gacha" violates the law.

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The company, a division of Informa, the publicly traded Swiss publishing and events company, trains sales teams in a method developed 30 years ago by Neil Rackham, an English behavioral psychologist.

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Unmasking and measuring the extent of targeted dumping does not necessitate resort to the exceptional method for all sales.

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Even Apple changed its method of reporting iPhone sales recently, leaving many analysts scratching their heads about how to make financial projections.

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This would be equivalent to a 30% sales tax rate, as normally calculated (exclusive method).

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An example of a strategy is fundamental indexing, which is a method of weighting stocks by fundamental factors such as sales and dividends.

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