Deep Packet Inspection is a technology that like a hammer can be used productively to build a table or to brake somebody’s head .
This technology allows any type of IP network that is not an end on a communication to be able to “listen” to what is going in that network (on layer 3 of OSI for the geeks) for any purpose.
The IP data packet goes through an inspection point, where it is analyzed or “listened to” and decisions can be made as for example in order to treat a virus, spam, intrusions and can be potentially used to take messures that alter the neutrality of the net, somethingh that ofcourse we don’t want to happen.
In my opinion the most important potential of this technology is being able to collect statistical information, that can be applied to different features, being the improvement of advertising relevance one of them.
Eventhough the advertising models based on this technology died thanks to a poor management from the referent of this industry such as NebuAd and I believe that it will be possible that new business will arise that will be able to use this technology, now reachable to more people to be able to develop applications that generate value without violating the neutrality of the net or the privacy of the people, taking advantage of the statistic value of the information that travels around the web, making it more “intelligent”.