Alliteration is a literary device which is a repetition of the consonants in a row, sound stressing syllable of a phrase.
Alliteration is a literary device which is used by the writer to emphasize something that he/she wants to express. To spot an alliteration, it begins with the same consonant sound.
Advertising slogan which uses alliteration is the Finest Berries Bite Into a Big Berry Blast Berry.
Herein. the repetition of consonant sound 'B' emphasizes the literary device alliteration.