I've an idea that (I believe) would be useful to people in their day to day real-life. If I get to the stage where I need to attract those people as users I wa

I've an idea that (I believe) would be useful to people in their day to day real-life. If I get to the stage where I need to attract those people as users I was thinking of targetting a small number of them that are geographically local; I know where they hang out. Just with old fashioned posters on notice boards, that kind of thing. They'll be a small set of guinea pigs to experiment on. As luck would have it, they're typically in touch with others of their kind so if they like the site I think they'll voluntarily tells others. My poorly made point is that old fashioned advertising may be an initial way to attract users if they're targetable.