How's the ad placement in your site? You should put them above the main fold of content and blend them well with the site background. This will increase the CTR. http://www.dagsensecodes.com/2006/11/10-tips-to-maximize-ctr.html
Make your ads blend into your page, i.e. make the same bg color and the advertisements the same color scheme as the rest of your design. 2% CTR is not bad though, if you want to increase revenue the most important thing is to increase traffic. The most important thing to increase traffic is to make a site worth visiting with loads of unique content.
Blend your Ads according to your website color This is most important and neglected part by new Adsense publishers. To achieve better CTR you need to format your ads according to color of your website. Here are few tips to properly format your Ads so that they don't look like Ads. •Make the background of your Ad the same as the background of your page. •Never use Adsense ads with border •Provide ample free space around your Ads. •Remove additional titles like "Sponsored Links" or "Advertisements" •Make the color of your URL and the color of your Ad's text the same. Let's hope using these tips will increase your adsense CTR