Traffic increase after domain renewal?

I had two domains renew this week, I paid for another two years. Traffic has doubled on both, and adsense has doubled as well. Nothing has changed except they were paid up for a couple years. Anyone else had this happen? Am I nuts? Nothing else has changed but the stats.

All things equal, if you have 2 identical websites, but 1 of them has its domain registered for the next 2 years versus a domain that is registered for 1 year - the search engines will look more favorably upon the 2 year registered domain.

SEs want domains that have the owners believing it will be around for a while.

Are your hits coming from SEs? That's all I can think of.