The company said it was unable to ship any DVDs on Tuesday, some on Wednesday and none so far on Thursday.

"Unfortunately, we continue to experience significant shipping issues as of Thursday morning," said Andy Rendich, head of operations for Netflix, in a company blog post.

"We were able to ship some DVDs from about half of our distribution centers yesterday but we haven’t yet been able to resume shipping this morning. Our engineers continue to work around the clock to restore normal operations. In the meantime, we’re notifying affected customers via personal email."

Netflix said it doesn’t know the cause of the outage and would not give a timetable to when the issue would be resolved. "We’re as frustrated about this as you are and we once again apologize for the inconvenience," Rendich’s blog post said. "Thanks for your patience."

Netflix customers commenting on the blog post have already begun to run out of patience. "Patience? I’ve run out of patience. This is unacceptable and as it’s been a week, the credit better be at least 25% of my monthly fees," wrote one commenter. Adding " ‘Around the clock’ yeah, and you’ve got a bridge in Brooklyn you’d like to sell me."

Another commenter wrote," I’ve already signed up for Blockbuster and will be testing your delivery times." While another wrote," This is all unacceptable I am sure a lot will agree with me. I really do not want to go to Blockbuster but so far I see no other choice."

It is only the second outage in the company’s history. The first was in March, when the Netflix Web site and its shipping system were down for close to 24 hours.

After that outage Netflix applied a 5 percent discount to the monthly bill of customers who experienced a delay in receiving their films.