In a nutshell: The PlayStation 4 has been a resounding success for Sony, but with its successor arriving this year, sales declined 25 percent over the holiday season. There were 6.1 million units sold in the three months ending December 31, 2019, down from 8.1 million units during the same period one year earlier.

Sony's Q3 results for the financial year 2019 show that sales in its Game and Network Services segment, of which the PS4 is part, was down 20 percent to 158.5 billion yen ($1.46 billion). The company blames the decline on falling PlayStation sales, a decrease in sales of non-first-party games, and the effect of foreign exchange rates.

14.7 million PS4 units were shipped in 2019, down from 2018's 17.7 million. With many consumers holding on to their money until the PS5 arrives, PS4 sales are expected to decline faster in 2020. The machine has now sold 108.9 million units across its lifetime, making it the second-best-selling console of all time, beaten only by the PlayStation 2's 155 million units.

Game sales also fell last holiday season, down from 87.2 million units in 2018 to 81.1 million in 2019. We also see that buying games digitally is becoming increasingly popular, with 49 percent of those sold in Q3 being digital versions, up from 37 percent last year. Across all of 2019, software sales reached 240 million, 110 million of which were digital downloads (46 percent).

While the PS4 is coming to the end of its life cycle, there are some first-party titles arriving this year that could encourage people to buy one of the consoles. The Last of Us: Part 2, Ghost of Tsushima, the Final Fantasy VII remake, and, of course, Cyberpunk 2077 all arrive in 2020. We might also see the PlayStation 4 receive its first price cut since 2016 at some point.