all you must know to earn thousands of dollars with adsense is you know what subject is better to write about in your site. insurance is one of the best subjects.
Every article can earn money. It depends how attrative your content is. The same question if I were to ask, what kind of movie is most profitable? Fiction or non-fiction? It depends your actors, actress, the script, movie editing and etc.
good job trying to paste your stupid ass adsense ad WITHIN a post. why 6000 dollars? Why not 7000? 8000?
Writing professional catchy articles requires advanced English, communication skills, expertise in the field and some talent. If you have these you probably figured out a better way to make that money already.
lol just a bit of advice - it's not really about the topic.. it's how much traffic you can get (and from where) that determines your AdSense revenue. this is true not only for AdSense but generally for all CPV/CPC traffic. for CPA and paid memberships, the buying intent of the niche also becomes important.