Video rental king Netflix Inc. (Nasdaq: ) years ago usurped Blockbuster Inc. (NYSE: )’s throne as the No. 1 video rental outlet, but now it’s focused on cementing its status as the market leader as other video rental companies struggle to play catch-up. 

Blockbuster, still king of brick-and-mortar rental stores, learned first hand the threat an innovative upstart can pose when it ran up against Netflix’s DVD-by-mail business model.

With movie theater tickets costing upwards of $10 (and that’s not including the popcorn or sodas), Netflix’s $8.99 1-DVD plan with unlimited exchanges and streaming video access represents a decidedly better deal for consumers that are tightening their spending amid rising unemployment and waning confidence.

Netflix celebrated its 10 millionth subscriber in February, noting that it added more than 600,000 net subscribers since the beginning of the year. In its second quarter ended June 30, Netflix said it had a total of 10.6 million subscribers, with paid subscribers representing 98% of the membership. The company expects its total membership to rise to between 11.6 million to 12 million by the end of the year, upping its previous quarter’s guidance of 11.2 million and 11.8 million.

Churn, a measurement of customer cancellations, rose to 4.5% in the second quarter from 4.2% a year ago, Netflix said.

"It could be the economy," Netflix Chief Executive Officer Reed Hastings said of increasing churn in an interview with The Motley Fool. "It could also be that we make it very easy for subscribers to put their accounts on hold if they go on vacation or don’t have enough money for a month or two. When a subscriber goes on hold, we count that as a cancellation. What you can look at - as a good stable indicator - are net additions. And net additions continue to grow." 

Netflix’s top and bottom lines continue to grow as well. Revenue grew to $408.5 million in the second quarter, up from $337.6 million in the same period a year ago. Profit grew to $32.4 million in the second quarter, up from last year’s $26.5 million.

As subscribers, sales and profit rise, so too does Netflix’s stock. Shares of Netflix have jumped more than 45% since the start of the year, and managed to sidestep the doldrums experienced by the markets in March.

Still, it’s no time for Netflix to rest on its laurels, lest it suffer the same fate as Blockbuster. That’s why CEO Hastings is quietly preparing for the death of DVDs themselves. Ultimately, consumers will one day dump the plastic discs in favor of movies delivered straight over the Internet, Hastings told The Wall Street Journal.

So Hastings, who is a self-proclaimed student of companies that stumble by failing to adapt to technology shifts, is quickly trying to shift Netflix’s business so that more videos are available online.

While Hastings is having success in getting Netflix instant video onto devices, the biggest challenge facing his company is convincing Hollywood executives to license their content. While 12,000 choices may seem like a lot, many are older AAA movies or TV shows, or newer movies that weren’t commercially successful.