In the "Agile" community you will hear the cry for frequent delivery of features to the customer so that the customer can know that the product is progressing.
In the old days these were called "demos" or demonstrations of the product.
Why are the developers trying to "sell" frequent delivery of developed features? Isn't this backwards? Shouldn't the Product Managers or the customers be the ones that are saying, "Hey, we really want to see what you have developed thus far. Can you show it to us?" How did this get twisted around such that it is the Developers trying to sell the idea of frequent demonstrations of the ever increasing functionality to the Product managers, the Process managers, and the customer!
Dr. Peter Venkman: This city is headed for a disaster of biblical proportions.
Mayor: What do you mean, "biblical"?
Dr Ray Stantz: What he means is Old Testament, Mr. Mayor, real wrath of God type stuff.
Dr. Peter Venkman: Exactly.
Dr Ray Stantz: Fire and brimstone coming down from the skies! Rivers and seas boiling!
Dr. Egon Spengler: Forty years of darkness! Earthquakes, volcanoes...
Winston Zeddemore: The dead rising from the grave!
Dr. Peter Venkman: Human sacrifice, dogs and cats living together... mass hysteria!
Well here we are in mass hysteria. The Developers are the ones crying out to have frequent demonstrations of the current state of development.
In my opinion the main point of frequent releases or demonstrations (depending on your deployment model) are primarily for showing where we are at in the development of the product. Once we know where we are at we can then say things like "Six months ago we had those features and now we have those features plus these features. We are making progress." Knowing where we are and where we have been and how long it took us to get here are facts used to progressively refine estimates of how much longer it will take and at what cost. This is a part of honesty in reporting.
On a side note, somehow along the way various Anti-Agilists have distorted the weight of reporting with that of getting feedback from the customer. These Anti's have created a straw man to tear apart. The claim is that incremental development (yes, that is what every Agile process I understand uses) is some lazy, shady, and shoddy approach to software requirements. The straw man goes like this, "Agile development does not try to understand the task at hand and do their due diligence in understanding what the customer really needs. Instead they hack out some code and show it to the customer and say 'Is this what your wanted?'" Maybe some idiotic process out there does that and if so I will stand by my description of it being idiotic.
The key to frequent delivery is to show where we are in the development of the product. Once you have shown this to someone it is natural for them to want to give feedback. But the intent was to deliver exactly what the customer wanted the first time. It was NOT the intent to deliver some overly simplified hack of some half known requirements and then refine the requirements because you knew you had developed a piece of junk.
I have delivered many features in an incremental fashion that were 100% correct when the user saw them. There was no need to make any changes what so ever. That is the goal. Showing the progress as the product comes together allows for everyone to know the REAL status of development and to fine tune other events and tasks that will need to be performed in order to have a successful and thoughtful product launch.
Isn't this stuff just common sense? Maybe cats and dogs are living together and I missed the memo.