Is it normal to receive the default "Your Ad Here" ad on every single placed ad space? I would absolutely love to use this, but there's no point if I'm not going to get a single ad. Is there some waiting period or something?
Ads are only shown if advertisers buy one for your site. If they don't, you will not be earning money.
It's not an ad network like Adsense; it's like BuySellAds (ie. the advertisers manually choose which sites to advertise on and how much they want to pay).