LMAO - you're right about that!
In all fairness though, sometimes when the price goes down, the promotions are not the same.
For example; I had a client the other day where they contacted me and said they saw where the price of their cruise went down. I checked and sure enough, the cruise line is now offering guarantee cabins for much less than they originally paid for their cabin. However, if they choose to take the new rate, they'll lose the special they originally had, i.e. pre-paid gratuities that were worth $84 per person. So the client had a choice to make; do they move from the cabin they really wanted and lose their pre-paid gratuities or do they choose to get a guarantee cabin where I have no idea where they'll be but they'll save money overall?
With all that said, sometimes there aren't alot of options, especially after final payment has been made. It will depend on the special that was booked, the cruise line, and other factors that will play into the decision making process.
Obviously, this is a choice for the client to make. But the bottom line is, it's their decision to make. An agent's commission has nothing to do with it and what I would do is irrelevant. It's all about presenting the facts and then the client deciding what's in their best interest and what they want to do.
And yes, these big online sites are all about the money and not about the service, so you really have to look at all the information and decide what's in your best interest.