Though NeoKylin is not a free OS, I guess Dell may get paid for preinstalling NeoKylin from China Standard Software. According to this source (in Chinese) [1], China Standard Software got 0.5 billions RMB funding ($800M) from the gov. The gov measures its performance by some methods including the shipping number of NeoKylin. It's natural for Dell and China Standard Software to have such a contract. One preinstalls NeoKylin for money. The other has the number to get funding from the gov. Though nobody uses it, two companies get money.
[1] http://baike.baidu.com/view/4920982.htm