Sony has told the official PlayStation forums that the Go!Messenger service run in conjunction with BT will shut down at the end of March.
"The Go!Messenger service will be withdrawn by BT and Sony Computer Entertainment (SCEE) from 31 March 2009," a statement read.
"Although Go!Messenger brought innovative communications features to the PSP community, the service has not developed the base of users that we were hoping for."
Introduced in the 3.90 firmware for PSP this time last year, Go!Messenger is a free instant messaging program compatible with the Go!Cam for video chat.
In a brief FAQ about the shutdown, Sony elaborated: "Although it proved a popular concept, achieving a significant number of registrations, it didn't gain the number of regular users that BT and SCEE were aiming for."
The platform holder also said that "future products" will be released to take advantage of the Go!Cam.