Amazon.com posted earnings that beat Wall Street expectations Thursday even though profit fell as the online retail colossus invested in shipping centers and digital entertainment content.

Amazon reported a profit of $82 million on net sales that rose 22 percent to $16.07 billion in the first three months of this year. The Seattle-based firm made a profit of $130 million in the same quarter in 2012.

Shares slid more than five percent to $260.69 in after-hours trades that followed release of the earnings figures.

The company has been investing in its own shows for online streaming and getting content from partners as it competes with Netflix, Hulu and other online film or television service providers.

"Amazon Studios is working on a new way to greenlight TV shows," Amazon.com founder and chief Jeff Bezos said in a statement.

"The pilots are out in the open where everyone can have a say. Our customers will determine what goes into full-season production."

Amazon Originals programming is available at a Prime service that offers free two-day shipping on orders, along with online streaming of films and television shows, for an annual subscription fee of $79.

Amazon has been beefing up its distribution network to speed delivery of online purchases to customers.