Suicide is a momentary decision which is quickly implemented. If this is delayed somehow- circumstances or otherwise- the offence cannot be committed. The best thing is not to let a person with suicidal tendency alone. Nobody consults someone or visit facebook before suicide.
Even I also no hope that people will visit facebook before commiting suicide. Because if a person strongly feels to commit suicide then that person will commit.
It is a step taken by Face book to bring down the volume of suicides that happen every now and then in our society. It might prove helpful for those who wants to give a second thought about it and face book is really doing something worthy in this regard.
I hope it might be successful in its attempt to slow down the number of suicides that are taking place...!