Question about Youtube message software

For years on youtube I have been getting those usual inbox spam messages and never really thought much about them, because it seemed like to simple of a spam tactic to really work but now that I have been hardcore into learning internet marketing its made me wonder. Anyway my question is 1. Is the Youtube message spam tactic still a relevant tactic generally speaking? and 2. If so what is the best software to use to acquire usernames and mass message on YT? Thanks