NASHVILLE (AP) - Amazon turns 20 on Thursday. Here's a timeline of 20 investment bets Amazon made in the past 20 years:

1995: Amazon opens its virtual doors as an online bookseller.

Late 1990s: Amazon invests in startups like Pets.com and kozmo.com that promised to change the way people bought pet food and ordered delivery items. But they both went bust shortly after the bubble burst in 2000, causing Amazon to lay off some staff and scale back elsewhere.

1999: The company launches Amazon Auctions, a separate site that resembled eBay's auction sites, which did not succeed. "I think seven people came, if you count my parents and siblings," reminisced founder and CEO Jeff Bezos.

2000: Amazon launches Marketplace for third-party sellers to sell on Amazon. Today, 40 percent of Amazon's units are sold by more than two million third-party sellers worldwide.

2005: Amazon starts its Amazon Prime loyalty program: $79.99 a year for free two-day shipping. Today, there are an estimated 35 to 40 million members.

2006: Using technology developed for Amazon's internal infrastructure, Amazon begins offering businesses a suite of products and services by way of the "cloud," remote servers that enable users to access applications on any machine with an Internet connection. Revenue rose 49 percent in the most recent quarter to $1.57 billion.

2007: Amazon launches the Kindle in 2007 when e-ink was just going mainstream as a device for reading digital books. Since then, it has branched out into several different versions of the Kindle including a kid-friendly version, Fire color tablets and dedicated e-book readers

2007: Amazon launches a niche website in 2007 called Endless.com that focused on selling high end handbags and shoes. The site failed to attract fashionistas or carve out much of a distinctive niche for itself, and it was shuttered in 2012.

2009: Amazon begins offering Amazon Fre sh grocery delivery in Seattle. It has since expanded that service to Los Angeles, San Francisco, Philadelphia and parts of New York. After a free trial period, for $299 a year members get same-day and early morning delivery on groceries The goal is to expand to more cities over time, but a nationwide rollout has proved elusive so far.

2010: Amazon Studios launches in 2010 to create and acquire TV shows to supplement its Prime Instant Video offerings. In January 2015, its original show "Transparent," starring Jeffrey Tambor as a transsexual dad, won two Golden Globe awards.

2012: Amazon buys robotics company Kiva Systems in 2012 and has been implementing robotic technology in its warehouses to speed distribution.

2012: Amazon launches Amazon Game Studios. It has been beefing up the unit ever since it launched the Fire phone and Fire TV offerings last year in order to offer stronger gaming options for those and other platforms. But there hasn't been no breako ut hit as of yet.

2013: Bezos announces on "60 Minutes" that the company is developing drones to deliver packages to customers in 30 minutes or less. Amazon has been testing advanced drones abroad and the FAA hopes to have drone regulations in place within the next year.

2014: Amazon launches its Fire smartphone with features like visual-recognition technology. It received mediocre reviews, a steep price cut to entice buyers and significant write downs on the cost of developing the phone.

2014: Amazon has a public spat with publisher Hachette. It was reportedly over e-book revenue. It led to the largest U.S. bookseller removing pre-order buy buttons, cutting discounts and reducing orders for books. The rare public fight led to a black eye for Amazon's image. Eventually Amazon and Hachette signed a new contract.

2014: Amazon opens its 3D-printed products store in July 2014 to let customers have access to 3D printing technology. With 3D-printing expecte d to eventually upend the manufacturing and retail industries, the store gives customers a glimpse of what is to come.

2014: Prime Music streaming music service launches and offers Prime members access to tens of thousands of albums from artists including Beyonce, The Lumineers and Macklemore & Ryan Lewis. But there's no deal with top-ranked Universal Music Group. Amazon says "several million" Prime members listen to Prime music each month.

2014: Amazon surprises many when it made a nearly $1 billion bet on videogame streaming site Twitch. But a year later, it's not clear what Amazon's plans for the site.

2014: Amazon debuts the Echo, a WiFi-enabled speaker that responds to voice commands to play music, give updates on news and weather and even reorder some products. The Echo, which sells for $179, can also sync with Belkin WeMo and Philips Hue products to control home light bulbs and other devices.

2015: Amazon debuts the Dash button: stand-alone buttons you can push to reorder common household goods like Tide detergent. The buttons are invite-only and can be requested via Amazon's web site.

2015: The final frontier for Amazon is finding new ways to speed up delivery time, or so-called last mile delivery. They've rolled out Sunday delivery via U.S. Postal Service and reportedly have been in tests with startups Uber and Postmates.