The landscape of the NBA changes each summer due to the shuffle of talent that occurs with free agency.
In today's NBA market, good teams struggle to retain all of their assets due to a punitive luxury tax and the way in which front offices are willing to overpay for players in order to improve.
With the Bird Rights in place, free agents are often better off resigning with their current team, though this doesn't always occur.
Successful GMs are able to receive maximum production from their payroll, as very few owners are willing to shell out the $100 million in player salaries that Los Angeles Lakers owner Jerry Buss will this season.
There is a finite number of ways in which a team can improve, with free agency being the quickest.
The problem with free agency is that teams often overpay for players, although this wouldn't be considered a problem by the players themselves.