t5forum allow you to post like guest, but there is an anti-bot captcha to solve for every post
thanks all man for your replies , I really appreciate it , i am having a offer to post some things in which the advertiser will pay me for it.If it works then i will let you guys know it.
Good old spamming.
Try to get on a forum that is at least a little bit related to what you're advertising (or has relevant subforums).
Have you considered reddit?
ps You can create email address especially for the purpose, so email verification shouldnt be a problem.