Good commercial takes off for these challenging types... (8)

I believe the answer is:

gadflies

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

'these challenging types' is the definition.
The definition suggests an adverb but the answer is not.

'good commercial takes off' is the wordplay.
'good' becomes 'g' (abbreviation).
'commercial' becomes 'ad' (abbreviation for advertisement).
'takes off' becomes 'flies'.
'g'+'ad'+'flies'='GADFLIES'

'for' is the link.

Can you help me to learn more?

(Another definition for gadflies that I've seen is " Small insects that bite cattle and horses".)

I've seen this clue in The Irish Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.