Invite codes

Last week I put some codes up for grabs. 3 of them were taken within a couple of days. Now, a week later, the three of them have combined for 1 post, 1 word. That is one letter each in a week time. I feel reluctant to give out more codes, even though I have plenty. Why do people beg for a code, if they aren´t going to use their LJ? Why do they take hours finding one, but not minutes to update? Why do I even bother to write a post about this subject?