Is a youtube poster bot against youtube's terms and conditions does anyone know, I was looking at buying a copy of this:

http://www.youtube-poster.com/

Obviously if this is against TOS then I dont want to buy it.

1st rule of thumb: If you suspect it to be against TOS, then it is.
And in your case, it clearly is. It's described in the community guidelines, which you must approve from the TOS page:
http://www.youtube.com/t/community_guidelines

Everyone hates spam. Do not create misleading descriptions, tags, titles or thumbnails in order to increase views. It's not okay to post large amounts of untargeted, unwanted or repetitive content, including comments and private messages.

Please take these rules seriously and take them to heart. Don't try to look for loopholes or try to lawyer your way around them—just understand them and try to respect the spirit in which they were created. Violations of the Terms of Use may result in a warning notification or termination of your account. If your account is terminated you are prohibited from creating any new accounts.

thought so thanks very much