That was fast.

Amazon.com (AMZN -2.56%) reported blockbuster earnings last night that are sending shares to all-time highs today. There's plenty to dig into, but CEO Jeff Bezos included a particularly interesting tidbit in the press release. In highlighting the progress that the company has made recently with Alexa and its family of Echo devices, Bezos said that Alexa has now surpassed 25,000 skills.

Echo Plus on a nightstand

Echo Plus is one of the latest Alexa-enabled devices. Image source: Amazon.

25,000 and counting

In early June, Amazon hardware chief David Limp had an interview with USA Today and expressed a willingness to collaborate with Apple (AAPL -1.22%) to allow Alexa and Siri to work together. At the time, Limp disclosed that Alexa had 13,000 skills. In other words, Amazon has nearly doubled Alexa's catalog of third-party skills in less than five months.

Amazon is dramatically accelerating the rate at which it is onboarding third-party developers to build skills for its voice-controlled virtual assistant platform. It all started in June 2015, when Amazon released its Alexa Skills Kit software development kit (SDK), opening up the platform to third-party developers for the first time. It took about a year to add the first 1,000 skills, but the catalog's growth since then has been nothing short of breathtaking.

Chart showing the number of Alexa skills over time

The catalog is taking off. Data source: Amazon. Chart by author.

If voice-controlled virtual assistants are indeed to play a meaningful interface role in the future of computing, Amazon is sitting with a comfortable lead that can largely be attributed to being the first major player to open up to third-party developers. Despite the fact that Siri was the first virtual assistant from a tech giant in 2011, Apple waited a full five years to release a Siri SDK for developers, even though it was immediately obvious that Apple should have done so right away. It's true that Apple generally doesn't place much value in being first to market, but that doesn't mean it should squander the times when it is, yet that's precisely what the company did. Apple wasted its first-mover advantage in virtual assistants.

The Mac maker only opened Siri up in June 2016. Alphabet subsidiary Google followed suit in December 2016 with Actions on Google, allowing developers to leverage Google Assistant. Microsoft announced Cortana Skills Kit less than six months ago in May 2017. It's not clear how many third-party skills and integrations Amazon's rivals have at this point, but it's safe to say it's a lot less.