Blue commerce

Blue often means something which is sexual in nature, as in "blue movies." But it also has many other meanings. "Blue Laws" were ordinances which prohibited businesses from operating on Sunday, so as not to offend Christian sensibilities. Blue can also mean sad, or depressed.

I've never heard of "blue commerce," so we'll have to hope that someone who has shows up with an authoritative answer.

Could be a reference to the "blue collar" population, but I think it has to do with any business that deals in sex, i.e. porn movies, adult toys, etc.

Where did you see the term used? That would help.

blue e-commerce = online pornography industry