This questions should not delve into PE vs IBD discussions but rather on the profitability of either side for an investment bank. I came across this question at an interview with an MM.
Interviewer: What is more profitable to an investment bank? Sell-side or buy-side engagements?
I don't remember the exact answer to the question but I think it had something to do with fees being collected upon successful transaction...
Could somebody enlighten me please?