TechNavio (the research platform of Infiniti Research) forecasts that "the Global Deep Packet Inspection market to grow at a CAGR of 32.98 percent over the period 2011-2015 .. the report also discusses that lack of awareness of benefits of DPI remains a leading challenge to vendors".
The CAGR forecast is very similar Infonetics' numbers - 33.6% for 2011-16 ($470M to $2B here). Key vendors covered in-depth are Sandvine, Cisco and Allot (according to Infonetics, Huawei led the DPI market in 2011).
"The influence of DPI technology is increasing in the network environment of service providers. They are integrating DPI technology in their network equipment. Service providers are using standalone DPI products for the core of the network and integrated DPI solutions for their access points to get maximum benefit from both types of DPI technology. Thus, network operators are using both types of DPI solutions for better network management”.