While length of credit card history can be a fairly important factor, I agree that it should not have much of an effect on a score down around 700. There would be other factors bringing the score to that level, and these would likely outweigh the credit card history/average age. For high scores (800+), the churning would likely have a more substantial impact.
Cheers.
That's debateable. My score has been around 800 +- maybe 10 points or so for about 8-10 years. Basically since I started checking. Nearly everything I've seen mentions 760 as the cutoff for the absolute best rates on loans FYI.
I only started churning cards abou 3 years ago or so and it has made absolutely no difference. If you subscribe to truecredit it will graph it for you, so I know literally month by month.
So my experience, which is based on a semi controlled experiment -- first I didn't churn them, then I did -- suggests there isn't much of an effect.
I have read what seems like speculation here that this will affect a credit score but no similarly clear conflicting report. Eg my score was X and then I churned citi cards and it went down.
I'm sure that's plausible too, and I'd love if others would share their experience.
But in the absence of credible reports to the contrary I'd argue that there is some evidence that churning cards has a low to negligable effect on people with good credit.