Almost all of their wars ended with trade concession treaties, and their law codes were unusually devoted to the subject of commerce. The Rus traded raw materials like fur, wax, and also slaves. We're not going to venture into the astonishingly intense etymological debate over whether the word Slav derives from the Latin word for slave, because there is nothing more terrifying and verbose than an etymologist's flame war. But yeah, the Rus traded slaves. They also relied upon agriculture, and your relationship to the land determined both your social status and your tax burden. And if you ever fell into tax debt, which a lot of peasants did, then you became bonded to the land you farmed for the rest of your life. I guess that slave-like dynamic is okay as a model for social organization, but if you step on the proletariat for too long, you might end up with a communist revolution.