With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Gong Yoo is best known by his pseudonym Gong Yoo.
text_B: Pay-per-call -LRB- PPCall , also called cost-per-call -RRB- is an advertising model in which the rate paid by the advertiser is determined by the number of telephone calls made by viewers of an ad .. Pay Per Call providers charge per call , per impression or per conversion .. It is similar to online pay per click -LRB- PPC -RRB- advertising , but induces the viewer to make a telephone call instead of viewing an external website .. pay per click. pay per click. Both enterprises looking to reach certain locations , or local / regional businesses can benefit from Pay Per Call campaigns , because it allows customers to talk with the seller before buying a product or service .. Vendors of pay-per-call advertising attribute the growth of the model to the popularity of smartphones and claim that it reduces the costs of on-line click fraud .. click fraud. click fraud. Pay-per-call advertising is not to be confused with premium-rate telephone numbers .. Pay-per-call is the inverse of a premium telephone number , in that the advertiser who receives the call , not the caller , is charged for the service .. Since it is cost per lead advertising , the rates are higher than for toll-free telephone number service .. cost per lead. cost per lead. toll-free telephone number. toll-free telephone number. In general , the advertiser is only billed for calls that last at least one minute .. The duration of interactions -LRB- since callers spend more time interacting with the business on the phone than looking at their website -RRB- and the probability of fraud through calls is significantly reduced are factors that might increase Pay Per Call pricing , but also increases its effectiveness .
not_related.