You have never had people call you asking for a quote on a trip (which is the same as they can get direct) and then move on to the next agent all the while not returning phone calls or emails. It also depends on what exactly you define as good service. Taking an order takes very little skill and is certainly not service by any definition.
I've had 30 years experience in the hotel, bars and restaurant business. It's called the hospitality industry for a reason. It's all about service... so indeed, while I haven't sold cruises, I know a lot about service.
And through my high school and college years I sold men's clothing, on commissions... so I know a bit about working for commissions, and spending time, and losing customers in spite of it.
Hey... if you can find folks willing to part with larger portions of their hard earned money to get on a ship with tons of folks who've paid less, you had better do everything you can to keep them