It has been known for months that the PSP has been getting fewer releases while publishers have scrambled to produce more titles for the Nintendo DS. (See, for example, this study on Edge Online showing releases per year on the PSP.)
The figures reported by Game Informer make crystal clear just how many more releases the Nintendo DS has received, and shows that those Nintendo DS titles enjoy higher per-title average sales.
Total Software Sales and Tie Ratios
However, we can also use the figures above to give a somewhat different perspective on the handheld software market. In particular, we can compute the total software unit sales for each platform.
Through a greater number of titles and greater per-title unit sales, the Nintendo DS has moved twice the volume of software that the PSP has in its lifetime.
Moreover, we can use total software sales and total hardware sales to get an estimate of each system's tie ratio. (Recall that a tie ratio is the total software unit sales divided by the total hardware unit sales. It serves as an average software units per system sold.)
The tie ratio for the Nintendo DS appears to be around 4.8, while the ratio for the PSP is around 4.2. For the sake of comparison, the tie ratios for the current generation of consoles range from 8.1 on the Xbox 360 down to 5.4 on the Nintendo Wii.
Given that a system with particularly strong hardware sales can see its tie ratio drop, the Nintendo DS tie ratio estimate is quite strong given how well it has sold, historically.
On the other hand, the lower PSP tie ratio is in keeping with that system's robust hardware sales with weaker corresponding software sales.
Top 5 Software Titles
Game Informer's article also shows a top 5 software list for the PSP, based on LTD software sales, according to the NPD Group:
The NPD Group graciously provided Gamasutra with a corresponding top 5 software list for the Nintendo DS.
Each title in the PSP top 5 is a third-party title and, moreover, not exclusive to the PSP. While the GTA titles each started out exclusively on the PSP, they were each later ported to the PlayStation 2.
Conversely, the titles on the Nintendo DS list are all published by Nintendo (i.e first party titles), and most of them are exclusive to the system.
Super Mario 64 DS is a port of the earlier Nintendo 64 game of nearly the same name, while Mario Kart has had iterations on four Nintendo consoles.
Furthermore, the best-selling PSP title still has lesser sales than the fifth best-selling title on the Nintendo DS.
In fact, the Game Informer article elaborates on the scale of Nintendo DS software sales, explaining that 20 games have exceeded 1 million units in sales; by comparison only the three PSP titles shown above have sold over 1 million units in the United States.