SEOmoz did their SEO industry survey this year and received over 10,000 responses. I strongly recommend you skim the report, if you are in the industry. The responses can be found at SEOmoz.

Here are some data points I personally found interesting, but there is a lot more data here:

Those operating outside Google’s guidelines are over twice as likely to have filed a spam report about others.30% of broker-based link buyers have sent a re-consideration request to Google (compared to 12% in the general population)The total PPC spend has increased to over $180m / month.SEO outsourcing and consulting budget of around $18m / month (or ~$225m / year).

For the full results, click here.

Forum discussion at Sphinn.