Not always the products of great minds (3,5)

I believe the answer is:

big ideas

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'not always the products' is the definition.
I know nothing about this answer so I can't judge whether this works.

'great minds' is the wordplay.
'great' becomes 'big' (similar in meaning).
'minds' becomes 'ideas' ('idea' can be a synonym of 'mind').
'big'+'ideas'='BIG IDEAS'

'of' is the link.

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

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