http://therealsocom.com/2012/06/27/ex-zipper-employee-sends-anonymous-letter-to-therealsocom-com/
Some quotes
"Hi everyone,
So I am a former Zipper employee who worked on MAG and SOCOM 4. I will not tell anyone who I am as per the separation agreement with Zipper/SCEA, I cannot legally make disparaging remarks against either company."
"The biggest issue with SOCOM 4 was there were too many chiefs and not enough indians. Too many folks from within Zipper and SONY were making decisions."
"Ultimately S4 was a failing on two fronts, a developer which was not brave enough to fight for what they thought was right, and a publisher which felt that the best thing for S4 was to copy elements from Uncharted, Killzone, CoD and Infamous."
It's clear that this isn't the case for all of SONY's studios but I guess SONY lost a lot of faith in Zipper at some point.
Zipper was aqcuired by SONY in January 2006. They released SOCOM:Combined Assault for the PS2 and SOCOM:Fireteam Bravo 2 both on November 7, 2006 that year. Combined Assault got very average reception (PS2 game) and Fireteam Bravo 2's reception was really positive (PSP). Fireteam Bravo 2 (PSP) has retail sales at 1.03M on this site and Combined Assault (PS2) is at 2.04M.
MAG relased January 2010 (about 3 years 1 month later) . Sales are at 1.24M and reception was between average and generally positive.
4 ≈ One