Bro, I was injecting a london broil with marinade.... using a big as 6ml marunade injector with a needle on the end.. it was cool because if you want an idea of how the gear goes in the muscle you can see exactly when doing this with meat..
when I injected the meat with the needle very deep, the marinade stayed in the meat and you could see the meat swell slightly in that area..
however, when I injected the needle only a half an inch, the marinade sprayed (some of it) back out the injection hole, showing that when not going deep enough into the muscle, the gear could be lost between skin and fatty tissue. I guess this is common sense for most, but some are careless with injections and are probably loosing a good bit of gear.
When doing injections, VERY IMPORTANT:
be sure to hit muscle at 90 degree angle, and be sure to press and go deep as hell