i have seen this, especially in "specialty" areas, such as or, icu or for new grads. i don't necessarily agree with it, but it costs a huge amount of money to train a new nurse. think about it: when you are in orientation, you are not a productive staff member. all the money they are paying you is not accounted for by a "return" (for lack of a better word), other than your education. the facility does not get any patient care from your efforts. yes, you may be taking care of patients, but that care is being "charged" by the salary they are paying your preceptor. who, by the way, is probably being less productive than they would be should they be working on their own. (this is, of course, in an "ideal" preceptorship arrangement where each preceptor has only one orientee and no other duties). and then there are the classes they have to send you to.....plus, some hospitals pay preceptors more. it all adds up, quickly. in the hospital system that i work in now, it costs between $30,000-$50,000 to train a new hire, depending on the level of experience.
when you look at it from a financial standpoint, it becomes easier to see why a facility would want a commitment before agreeing to hire someone new. especially in units that have a high turnover rate, or places where new grads go to "get experience," and then move on to something else. i think some icus have implemented this kind of contract due to nurses coming in to get their experience for anesthesia school and then moving on. when i was in school, the floor i worked on (basic med-surg) was requiring a contract of 1 year for any new-grad hire. there wasn't a nursing shortage at the time in that area, though, and they could afford to make such a demand. i don't think i've ever seen an or that would hire someone without a contract.
as far as residents go, the hospital gets a pretty big return from their services. the hospital is able to charge for the services they provide. i'm not sure of how all of the billing works out, but i'm sure the hospital gets a cut somehow. they also do much of the grunt work that the attending physicians don't want to do (for basically a fraction of an attending's salary), which keeps the attendings happy. (the hospital i worked in when a nursing student was a very small hospital, no residents. we had one surgeon who always wrote on his post-op orders to "page ho for temp >101.5....etc. every time i took that order off i laughed to my self thinking "you are the ho in this hospital"