Pay Per Click on the decline

Pay Per Click is a tool that caught on quick and grew rapidly but has continued to increase at a decreasing level. What is contributing to the lag? I came across a podcast where Steve Rubel, SVP of Edelman's me2revolution, gave his input on the 5 reasons for Pay Per Clicks recession:

1. Unnecessary clutter around ads
2. Focus on traffic opposed to navigation on site
3. Rising costs (about 33% each month)
4. Sponsorship
5. Trustworthiness

Will this be a trend that dies out or will every advertiser use this technique to increase sales? If this is a trend that will be universally adopted, an action prospective opposed to a traffic perspective needs to be the key focus. With great keywords lists, tracking, management, strong campaigns and landing page testing.