My bet is that these people don't notice the requests, though they should, or that they think they added you and didn't. I'm your friend ahuyevshi.
However this is a good post to alert people to the "friend" option. A message would be sent and I believe it shows up under "Messages"...then within the User's CP (control panel) the "Contacts & Friends" window would open if one clicked on the friend request message. If anyone has any doubts, just go in through your User CP (see the upper left hand corner of the screen) and go to Contacts & Friends...and see if you have any pending friend requests.
The other day, I thought I had OK'd someone only to find I hadn't quite clicked the necessary option.