If you're lucky, an advertiser hasn't realised it's the holidays and is bidding up to try to increase click-throughs (this is about my lowest traffic and revenue week of the year), or has fumble-fingered $xx when they meant xx cents for a bid!
The consistent trend I've seen is EPC going up. The $10 click was an outlier, but my average click is about 3 times what it was when I got started with AdSense--8 years ago! Of course, CTR is approx. 1/5, but I've got more pages with ads on them, so income is about the same.