Netflix continued -- a mini part 9

Netflix watchers will definitely want to go read a fascinating article called An Analysis of Netflix's DVD Allocation System by someone who only goes by his email address "dvd-rent-test." His argument:

Netflix uses the number of movies you rented in your previous billing period to determine your priority in getting movies. The more movies you rented during your last billing cycle, the less chance you have of receiving a movie versus an individual who has rented fewer movies.

Very interesting. I don't think there's enough data here to confirm that this is indeed the case, and I'm still holding out that there may be other rational explanations for why things happen the way they do for individual Netflix customers. His data does pretty well match my own experience using the service since August 2002. I looked back over all my Netflix automated emails, which are Netflix's "promises" to customers to manage their expectations as to when DVDs have arrived back at the company and when the next DVDs will arrive at my mailbox. The faster the I pushed the rental cycle turnaround (order 2 DVDs, they arrive in the mail, watch 'em both and return to USPS the next day), the slower the turnaround became at Netflix's end. I started noticing regularly that even if I returned two DVDs together, only one would arrive next, even though both were shown as "Now" in the availability column. First the automated emails said the next two DVDs would arrive on the same day. Increasingly, they didn't. Then the emails started indicating the next two rentals were coming on different days. It sure looked like Netflix was staggering the releases, throttling back on the speed at which I was renting stuff.

But it seems that Netflix is saying "a-a-aaa, not so fast" if customers push the rental turnaround cycle too aggressively. One possibility, as dvd-rent-test's data suggests, is that Netflix fine-tunes each customer's rental cycle, not doubt to control costs and balance long-term customer expectations. I'm doubtful that Netflix "punishes" some customers by giving them very long waits and other customers less or no waits at all for the same DVD title. I suspect wait-time discrepancies have more to do with supply and demand at different distribution centers.

By the way, there's a typical debate thrash going on over at Slashdot about dvd-rent-test's report.

UPDATE: Continued in Part Ten...

Posted by brian at April 23, 2003 06:17 PM