Comment on Google AdSense Ad Channels by SEO Dave.
Your site is relatively new and the Google cache shows a page from February with no content using another theme (no AdSense).
If you added AdSense to your blog before adding the current home page content, the AdSense spider will use that content as the basis for ads to serve also at first the ads aren’t always very good anyway.
When you add new content the AdSense spider has to reanalyse the content and determine new ads and it isn’t done in real time. This is why you can have poorly targeted ads on a site at first, takes time for Google AdSense to determine what a page is about and if you change the content of a page it takes time for the spider to pick up the changes and server new ads.
I’m guessing the home page didn’t look like it does now prior to adding AdSense or it’s just because you’ve added AdSense for the first time recently (or a combination of the two).
Sometimes ads aren’t very good, especially in a niche with not a lot of money from the advertisers. Classic literature (a niche I have a lot of content in) is awful AdSense wise, all the cheap ads show up because no advertisers are willing to pay a lot of money for that content.