" Contract feudalism," put simply, refers to the persistence of superior-subordinate relations reminiscent in substance to those under previous regimes of status, but under the guise of a de jure regime of contract. Lysander Spooner put it pretty well in Natural Law::
"In process of time, the robber, or slaveholding, class - who had seized all the lands, and held all the means of creating wealth - began to discover that the easiest mode of managing their slaves, and making them profitable, was not for each slaveholder to hold his specified number of slaves, as he had done before, and as he would hold so many cattle, but to give them so much liberty as would throw upon themselves (the slaves) the responsibility of their own subsistence, and yet compel them to sell their labor to the land-holding class - their former owners - for just what the latter might choose to give them. Of course, these liberated slaves, as some have erroneously called them, having no lands, or other property, and no means of obtaining an independent subsistence, had no alternative - to save themselves from starvation - but to sell their labor to the landholders, in exchange only for the coarsest necessaries of life; not always for so much even as that.
These liberated slaves, as they were called, were now scarcely less slaves than they were before. Their means of subsistence were perhaps even more precarious than when each had his own owner, who had an interest to preserve his life. They were liable, at the caprice or interest of the landholders, to be thrown out of home, employment, and the opportunity of even earning a subsistence by their labor". ( Lysander Spooner, Natural Law, 1892, retrieved 25th February 2008, http://jim.com/spooner.htm)
Although Spooner's primary focus was on agricultural wage labor, rather than the industrial and service kinds that predominate in our economy, the basic principle of labor's dependency when it has been separated from the means of production and subsistence is essentially the same. A worker who is utterly dependent on employment, in a market where those in search of employment outnumber the available openings, is dependent on the whims of an employer for his food and shelter. The greater his dependence, the greater the degree of his subjection to his employer's whims, both on and off the job." (http://www.libertarian.co.uk/lapubs/econn/econn109.htm)