Apple announced on Tuesday that App Store sales topped $10 billion in 2013, with December alone responsible for "record-breaking" revenues that exceeded $1 billion.

According to a press release issued by the company, this pushes the total amount that company has disbursed to developers to more than $15 billion, which indicates that the App Store has generated nearly $21.5 billion in total revenues for the tech giant since its 2008 inception.

Besides exceeding the national GDP of an alarming number of countries, App Store revenues have been accelerating almost constantly: It took nearly two years to generate the first $3.6 billion in gross revenues--a sum that the company matched, on average, in every single calendar quarter of last year.

In addition to its significant economic impact on the livelihood of developers large and small, the App Store has also reached increasingly impressive milestones in terms of app availability and downloads; back in October, Apple announced that more than one million apps had made their way on its online software marketplace--a number that, according to today's press release, includes more than 500,000 titles that are compatible with the iPad. Sadly, the latest numbers to come out of Cupertino do not include download numbers, which the company pegged at more than 60 billion in the third quarter of 2013.

These numbers are important for users, who continue to enjoy unprecedented access to software at little or no cost, as well as developers, who, despite being faced with increased competition, have access to a marketplace that continues to expand both in size and economic value.