Sales promo from mouthy person (4)

I believe the answer is:

hype

I'm a little stuck... Click here to teach me more about this clue!

'sales promo' is the definition.
I can't judge whether this definition defines the answer.

'from mouthy person' is the wordplay.
'from' indicates the answer is hidden within the clue.
'HYPE' is hidden in the letters of 'mouthy person'.

Can you help me to learn more?

(Other definitions for hype that I've seen before include "Salesman's exaggeration" , "Extravagant publicity or promotion" , "Promotional publicity" , "Build up" , "Plug" .)

I've seen this clue in The Sun.

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