SAN FRANCISCO — Netflix Inc.'s movie subscription service attracted 1.7 million more customers during the first quarter to fuel a torrid growth streak that has turned the company into a stock market star.

The results announced yesterday are the latest evidence of Netflix's rising popularity. The service has picked up more than 5 million subscribers in the past 18 months as more households embrace Netflix's DVD-by-mail and Internet video packages that start at $9 per month.

That has helped Netflix to boost its earnings by at least 22 percent in each of the past six quarters, including a 44 percent gain during the first three months of the year.

The strong start to 2010 emboldened Netflix management to predict the company could make as much as $144 million, or $2.61 per share, this year, up from earlier guidance of $137 million, or $2.50 per share.

Netflix ended March with nearly 14 million subscribers and expects to gain up to 1 million more by July. Although it began as a DVD-rental service and the discs remain its main drawing card, streaming video over the Internet has played an increasingly bigger role in the company's success.

The company has been aggressively pushing the Internet option to save on postage to ship DVDs. Netflix also wants to make sure it has a thriving digital video service to remain relevant as DVDs wane in usage.