It all depends on where you place the ads and how you match them to your sites look and feel, as this can help heaps. If you are monetizing your blog it is best to use g adsense and infolinks together. As this can be used together and will double your revenue. Its hard to make a real good amount with only 100 visitors a day. Try to use some of your tactics found on your site to get more traffic. More traffic means more money (bottom line).
Also, replying from the last message, within your google account make your site targetable for advertisers as this can up your CPC and CPA.
well with 150 visitors the most you can earn is about 2$ - 15$ a month, if you advertised a little bit and get around 1k and 2k visitors you will be earning a least 150$ a month.
Actually, it depends on the visitor. If you have more visitor then you will get more money. So, try to promote your site to get more visitor.