SAN FRANCISCO, California (AP) -- Manuel Villanueva realizes he has been getting a pretty good deal since he signed up for Netflix Inc.'s online DVD rental service 2-1/2 years ago, but he still feels shortchanged.
That's because the $17.99 monthly fee that he pays to rent up to three DVDs at a time would amount to an even bigger bargain if the company didn't penalize him for returning his movies so quickly.
Netflix typically sends about 13 movies a month to Villanueva's home in Warren, Michigan -- down from the 18 to 22 DVDs he once received before the company's automated system identified him as a heavy renter and began delaying his shipments to protect its profits.
The same Netflix formula also shoves Villanueva to the back of the line for the most-wanted DVDs, so the service can send those popular flicks to new subscribers and infrequent renters.
The little-known practice, called "throttling" by critics, means Netflix customers who pay the same price for the same service are often treated differently, depending on their rental patterns.
"I wouldn't have a problem with it if they didn't advertise 'unlimited rentals,' " Villanueva said. "The fact is that they go out of their way to make sure you don't go over whatever secret limit they have set up for your account."