He has way more endorsement $$$ than he did in San Fran, AND Davis is aspiring to be a movie producer, which is why LA had more appeal (Hollywood). Hard to produce movies from San Fran 9 months out of the year. Definite advantage for the Lakers and Clippers when attracting guys who are looking to get into showbiz.
MOST players want to win (a few like Maggette, could care less), but they also want to win while making as much $$$ as possible. If the Clippers didn't have a cheapskate for an owner THEY would be up there with the Lakers, NY's, Miami's, and Chicago's as top free agent destinations because of the big market and Hollywood in LA. Bigger market means more endoresements, TV commercials, national exposure, etc.
Why do you think Parker is ready to go to New York next year? He wants the exposure (and $$$) of the big market team that he can't get here in San Antonio making Gunn Nissan and H-E-B commercials.