Troika Games' Sales Figures

GameDAILY has issued a report on Troika's closure, including specific details on how well each of the company's games did commercially. The sales figures for Vampire: The Masquerade - Bloodlines surprise me the most:
Boyarsky, Cain and Anderson formed Troika in 1998 after leaving Interplay where they created the classic RPG Fallout. Troika only created three games in the past six years: Arcanum: Of Steamworks and Magick Obscura (2001), The Temple of Elemental Evil (2003) and Vampire: The Masquerade - Bloodlines (2004). These games catered to the niche RPG market, and although most were well received critically, the titles simply failed to generate enough revenue for the studio to survive. Arcanum was the company's best selling game, and it only managed to sell 234K units and generate sales of $8.8 million, according to the NPD Group. It was downhill from there; The Temple of Elemental Evil sold 128K units ($5.2 million) and Bloodlines sold a paltry 72K units ($3.4 million). It didn't help either that Bloodlines, which was published by Activision and powered by the Source/Half-Life 2 engine, was released at the same time as Valve's blockbuster first-person shooter sequel.

Even though Arcanum has a spot on my personal all-time favorite RPG list, I don't understand how it sold over three times as many copies of Bloodlines. Could piracy be a factor?