24/7 Wall St., LLC says, that while its initial sales were promising, the overall sales of the PlayStation Vita are poor, compared to the Nintendo 3DS, smartphones and tablets.
Released first in Japan in December 2011 and then globally in February 2012, initial sales of the PlayStation Vita were encouraging. By the end of February, the company announced it had sold approximately 1.2 million units, followed by an additional 2 million units of software for the handheld game console. Yet sales quickly declined. From its release date to June 30, just 2.2 million PlayStation Vita units were sold, far less than the 3.6 million units Nintendo 3DS sold in just its first month. Recently, Sony has clumped sales of the Vita and its predecessor, the PSP, together to avoid highlighting embarrassing sales figures. Frequent complaints about the Vita were that the $300 price tag was too expensive and that its game lineup was both weak and small, especially given the availability of cheaper gaming through smartphones and tablets.
Source