The PlayStation 4 was announced on February 20th, 2013 and was released November 15th, 2013. It was announced as having a new kind of super-fast RAM memory - 8 gigabytes of GDDR5. At the time, 8 gigs of GDDR5 was unavailable for purchase and equivalent memory cards cost around $1,200. It was also announced with an emphasis on social features, such as being able to share screenshots with others simply by pressing a button on the controller. One announced feature that was particularly intriguing to me was the ability to save your game state while the console is turned off; this enables a player to jump right back into a game when they turn the console on, making those 2 minute boot-ups with all the developer logos a thing of the past.
Speaking of the past, PlayStation has a rather interesting history which is worth summarizing here. Back in the late 1980s, Sony was working with Nintendo to create a CD add-on for the Super Nintendo Entertainment System. The day after Sony announced the add-on at a major electronics trade show, Nintendo announced it was partnering with someone else (Phillips) and thus publicly broke the news to Sony that they were abandoning their agreement. Even though Sony was not keen to join the video game business, they eventually released their already-developed technology and called it the PlayStation. The PlayStation would directly compete with the Nintendo 64 and vastly outsold it. In fact, the PlayStation would become the best selling home console of all time.
PlayStation's momentum continued with the PlayStation 2 - further securing exlusive games from third-party developers, organizing their own game development studios, and continuing their image branding as cool and hip. The PlayStation 2 would go on to outsell the original PlayStation and take the crown of Most Lifetime Sales.
One might imagine the PlayStation big-wigs were feeling pretty pleased with themselves and had a certain confidence when approaching the design of the PlayStation 3. The PlayStation 3 was announced as, of course, being super powerful and using a unique proprietary hardware structure called the "Cell Engine." Though the Cell Engine was powerful it turned out it's complexity frustrated game developers. Consequently, developers simply programmed games for the PS3s arguably less-powerful competitor (the XBOX 360) and then made a similar copy of the game for the PS3, thus negating any power advantage of the PS3. The PS3 also released a year after the XBOX 360 and Nintendo Wii, and at a higher price point. As a result of these and other factors (such as a truly perplexing advertising campaign), the PlayStation 3 struggled for years and trailed behind it's competitors. However, much of the PlayStation leadership switched around and excellent games were ultimately released for the system, and it did eventually outsell the XBOX 360. The whole PS3 experience did, however, seem to humble the PlayStation management and change their approach to their next system.
When the PlayStation 4 was announced it was touted as not only extremely powerful (for the price), but very easy to program for. They announced a variety of games from big studios, but also small, independently developed games. Though they didn't openly say they screwed up with the launch of the PS3, they seemed to give an air of returning to their roots. Fortunately for Sony, they would get their biggest sales boosts simply by not making the massive blunders of their competitors.
The Wii U had already released to fairly dismal sales before the PS4 was even announced, and so the XBOX One was their primary adversary. In 2013, Microsoft had announced a fair amount of unpopular aspects of the XBOX One, and by the biggest gaming show of the year (E3) people were not feeling to great about getting one. In fact, one Amazon poll was ended early because people favored the PS4 by a factor of 18:1. So why was the XBOX One so unpopular? Well, lots of reasons, but here are some big ones: It cost $100 more than the PS4 despite having about 50% less power; it required you to have a Kinect camera constantly plugged into the console which was always running AND sending data back to Microsoft; it would not work unless it was connected to the internet; and it did not play used games. Essentially, the Xbox would need to "check in" with Microsoft servers every day. If this check was missed, the console wouldn't work. If, during the check in, Microsoft was informed a game disc was played on your console that had already been played on someone else's console (i.e., a used or shared game), then it would disable the game disc.
All PlayStation needed to say at E3 was "PS4 Supports Used Games" and they were instantly the front runner by a mile. Simply stating that they were not changing their policy caused what has been described as the loudest and longest cheer in E3 history. It also spawned a viral video which featured the President of PlayStation. The head of Xbox would "resign" within a month and Microsoft gradually dropped most of the 1984-style aspects of the XBOX One. The PS4 would go on to sell more than a million consoles on release day and thus became the fastest selling games console of all time.