The problem is that Youtube has limited their private message system to a certain number of messages by hour per account, not per IP. That's why you can't avoid that restriction using the same youtube account, but there's no problem using another one. How much messages do you want to send? If you are looking to send between 200 - 300 messages a day (24 hs), you won't have any problem. I've got one developed on VB6 that I've been selling it on January. The main features are:
* 4 different predefined messages (To make it dynamic changing a few words)
* Attach any video of your account
* Configurable interval to send messages (Recomended at least 2 mins between each one)
* Statistics of messages sent
* Load youtube usernames from a text file (Easily configurable)
* Add youtube usernames to the list at runtime through GUI.
* Minimizable to task bar
If you are interested, please, reply this post (or PM me your skype or email to talk - I can't reply PM until 15 messages). I'm just registered here so I have no feedback... Anyways, I will not dissapoint you.
Shirko.