To sell more cameras. Probably they have streamlined production and the profit margin is higher. They do rebates instead of lowering the wholesale price because sometimes stores don't pass along the lower price.
A guess might be that they are trying to sell as many of the D2Xs before introducing a 8MP-10MP D3H or something.
Andrew A.K.A. Fundy
----------- Oregonian Nikonian presently found on Shikoku, Japan http://fundy.us
As far as I understand, the rebate was a reaction to the overwhelming demand for the D200, particularly among pros who ordered the D200 rather than drop $5k for a D2X. I'd love to see the price come down for good, but odds are that the rebate will stop when supply levels of the D200 stabilize.
This is heresay, but I've heard that many times the rebates are driven by currency differences. I would imagine this is just one factor more than "the single reason". I'm sure demand and competitors products play a role in this decision also.