"Throttling"
Given sufficiently speedy mail delivery times, customers on "Unlimited" plans who turn around their discs quickly enough can receive enough shipments in a month that the company's actual cost of delivery exceeds the subscription fee, making the company unprofitable. Even below this point, higher volume customers are by definition less profitable than customers who receive fewer discs per month. If these customers become too numerous, there are various measures which the rental company can take. One is the so-called "throttling" approach, which received a fair amount of publicity with regard to Netflix (which refers to the practice as a "fairness algorithm"). In this case, high-volume customers may experience a greater likelihood of (slower) shipments from alternative warehouses, when the nearest shipment centre does not have the requested movie. Also, if there is a high demand for a particular movie, it is more likely that an infrequent renter will get priority over the frequent renters, with the latter receiving a movie further down on their queue. They are also less likely to receive replacement shipments on the same day a disc is received. Similar "fair use" caveats can be found in the Terms and Conditions of leading UK companies such as LOVEFiLM. In Canada, Zip.ca switched to "Capped" plans (with additional shipping charges for rentals over the cap) in part to avoid implementing "throttling".
LOVEFiLM came under scrutiny from users over its claim to offer "unlimited" movie rentals. Some users reportedly found the company used long delays at the shipping stage to reduce the number of films a month a customer can rent. The company was subject to a dispute by the Advertising Standards Authority over the use of the word "unlimited" in their advertising. It was revealed that they practiced throttling. The company itself claimed that this "fair usage" policy means all customers get a similar service.
On March 2, 2006, Blockbuster announced that their service does not implement throttling. "We don't prioritize our customers' movie fulfilment based on how often they use our service, and we don't limit the number of movies a subscriber receives each month," according to Senior Vice-President Shayne Evangelist. However, the Terms and Conditions each customer has to agree to in order to subscribe to the service states "BLOCKBUSTER Online reserves the right to determine product allocation among members in its sole discretion. In determining product allocation, we use various factors including, but not limited to, (i) the historical rental volume for each subscriber, (ii) historical number of outstanding rentals relative to the maximum number of outstanding BLOCKBUSTER Online Rentals allowed under a subscriber's plan, and (iii) the average rental queue position of BLOCKBUSTER Online Rentals that have shipped to a subscriber in the past." concerning their Selection and Allocation of Product, which could be read as contradicting this announcement.
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