Adsense is a contextual ad provider and It provides ads relevant to content only when it can find out the content and keywords from that page. By placing the ad right after 1st post in a thread/page, we are helping adsense serve ads which are more relevant to the content. This will in most cases help members when they're looking for some quick help from their post. eg, a post started asking for windows related problem might actually show ads which links to the solution.
While doing all this, we are obviously hoping for a few more clicks from members and guests to run this website/forum properly. As we are growing rapidly, we feel the need for a better and reliable hosting etc. and for that we'll need money. Furthermore, the ads have been clearly defined and seperated from the content (marked as Sponsored Links). If you are not interested in that ad, you can pass it as yet another post. Where's the question of forcing smthing arise? I am sure this is not obstructing anyone's ease and convenience of browsing through the pages. I hope you can understand.