Do not be fooled by those traffic sellers promising thousands of hits an hour. What they really do is load up your URL in a program, along with a list of proxies. Then they run the program for a few hours. It looks like someone is on your site because your logs show visitors from thousands of different IPs. What happens in reality is your website is just pinged by the proxy, no one really sees your site. It is a waste of money.
Nice work Laura! This is going to be a great series. I'm working my way through SEOmoz's Advanced SEO Training Series (videos) Vol. 1 & 2 to build upon the advice and guidance that you and your team provided to me during my time at Yahoo!. Now many others will benefit from your knowledge, experience and passion for SEO strategy and tactics. Best wishes for great success in your new role.