How do you get people to join a Forum?

I started a Political and Current Affairs Forum called www.politicalforum.ie which is totally free, there are no advertisements on it and it was never designed to make money. Basically it is just a hobby. But I am finding it difficult to get people to join and interact. Has anyone got any ideas or will some people look at the site and see if I have done something wrong in the design. Thank you

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