Satisfied buyer of an electric fan? (4,8)

I believe the answer is:

cool customer

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

'an electric fan?' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'satisfied buyer' is the wordplay.
'satisfied' becomes 'cool' (I can't explain this - if you can you should give a lot more credence to this answer).
'buyer' becomes 'customer' (I've seen this in another clue).
'cool'+'customer'='COOL CUSTOMER'

'of' is the link.

Can you help me to learn more?

I've seen this clue in The Globe and Mail.

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