What do you say to explain ID?
Aah that old chest nut. A question that has a variable answers:
To the business man: ID is the physical, useful, usable and desirable embodiment of a brand. It is the marketing promise for-filled. The consumer satisfied.
To the lower/est common denominator: What was the last thing you purchased? "Blah" A product designer made you choose that one by making it look the like something you would want, at the price you could afford, over the other products on the same shelf / shop, etc ...
To engineers who think that ID/ers have no credibility then I would suggest that you do not really understand engineerings relative place within business. True, it is far easier / more common place for engineering to be mutually exclusive but that does not mean that ID has any less value ... to those businesses at least that understand the benefit of incorporating it into their strategy ... which as you (Guest) point out is limited by IDers ability to justify the features and benefits their skills can bring to businesses ability to make money ... and in the common language of business.