Power Steering Fluid

This is a fairly new service, traditionally mechanics would only recommend this if there was an issue with the power steering system and the fluid was very dirty, or if a pump or steering rack were replaced. Now shops are selling this service as a preventative maintenance service, and I'm not sold on it yet. It makes sense that the fluid gets contaminated and wears out, just like other fluids in the car, but I've heard of shops recommending this service at less than 20,000 miles, and that is not necessary. If I was going to do it, 60,000 miles seems about right to me. The real problem here, and with a lot of these "flushes" is that they are being pushed by shops that get kick-backs from the chemical companies that sell the flush chemicals, so right there I'm suspicious. Is a shop recommending this service for your 2009 Camry?