Setup Google Analytics and analyze the sources. Make sure you are not being clickbombed or scripted. Adsense also lets you use Google Analytics data as traffic justification in case they ever investigate your sudden fortune.
yes you should be worried; my adsense went from $5/day to $60/day because I was clickbombed. I woke up at 5am ready for work when I found out my account was disabled even though I had done nothing (i knew who had done it, i write a web site on Nigerian scams and they told me they would get me); my appeal failed and no reasons where given.
lol BigBadWolf, Dang thats some impressive impressions and clicks $100 a day Ive only hit $23 so far lol Earn about $1 a day right now. Great work! Id be happy as all and striving even harder to promote my pages. It can only get better!
If his impressions & clicks have no changed, he was not click bombed. He's just earning more per click.