OK, Call Me Stupid, Twitter Question

Stupid for two reasons, 1. that Im even using Twitter, & 2. Its got me stumped.

I dont trust Twitter but I have found myself in a situation where I need it. I am helping someone organise a UFO Convention in Australia next year. We are trying to raise support so our negotiations with the state Tourism agencys will go better for us. If they see we have enough people wanting it to happen, they are more likely to spend the small amount we need to make it happen. Dont laugh, it was the Ministers office who sent it to the media.

I joined Twitter 2 days ago. I have attracted a few followers, & I am following 10 related groups. Ive made a few tweets to let people know who we have speaking etc. I can see them on my page, & a whole heap of tweets from those I follow.

My problem is, I have tried to leave a tweet on their pages thanking them for their support etc. I cant see my tweets on their pages. What am I doing wrong ? I was under the impression if they are following me, they get the tweets I make, especially an @ tweet. Why can I only see them on my page ?

I wish I didnt have to use it but I have no idea how else to get the word out other than the guys website. We have all sorts of media waiting for us to give them a date, speakers are waiting to confirm our dates, I just need followers to show the Govt theres support for it, & I dont seem to be able to get a simple tweet to work

Thanks for the help.