Putting in a little bit of time to raise the fondness of the girlfriends can unlock their "special abilities": these can help in particularly difficult missions late in the game.
Like the other relationships that Niko has with his friends in GTA IV, favor can be gained with girlfriends by taking them to different venues around the city.
Spawn Super GT Dial "2275550168" on the cell phone.
Note: This phone number translates to "CAR-555-0168". Note: This phone number translates to "CAR-555-0147".
Or with a helicopter, snap off the blades at a height where Niko's girlfriend can get hurt but won't die.
Each woman has different tastes and will respond accordingly.
Reaching 100% fondness with all five girlfriends is not required to achieve 100% completion of the game.
If an Internet girlfriend's fondness is raised to a high enough level, her "special ability" is unlocked.
If Niko Bellic has a bad date or does not ask to come inside, the girl dumps Niko.