Possible Clues:

• By-product
• Prequel series, essentially
• Odds against snooker foul producing something advantageous?
• Incidental benefit of singular power when taking snooker shot
• Unintentional benefit of GP accident?
• ''Frasier,'' to ''Cheers''
• TV programme, follow-up to earlier successful one
• Profitable by-product
• Extra benefit of using faster deliveries only?
• "Rhoda" or "Joey," e.g.