Mobox Graphics shows an easy way to get that typed on text look in Ae using Character Offset.

One easy way to create that typed on text look in After Effects animations are to use the character generator and animate an offset to bring on the letters that you want. Check out this new tutorial from Mike Ridolfi (MoBox Graphics), which shows how easy it is.

The tutorial covers how to use the Character generator under the After Effects Type Animamtor’s menu. By adding a couple of range selector functions, you can have the characters get typed on by arranging the offset value.