The main persuasive technique in this ad is the celebrity testimonial. Beyonce is an icon, and people not only want to be like her, but they trust her. This leads to the rhetoric technique of ethos, because Beyonce and L'Oreal assure us that "once you find the one, you never go back" and that the product works well. Beyonce even goes as far as saying "there's only one true match for me". Also, flattery is used in L'Oreal's tagline "because you're worth it".