If you are a small to medium business owner, you need to understand Google Adwords and Google Analytics. In the past 3 years, we have found that business owners that understand both have greater success on the web. Owners that are in tune with the Internet market can also use the powerful reports to make informed changes to web and traditional marketing channels.
In the past 6 months I have seen a client go from little knowledge about the web to becoming a leader in Internet marketing for his product line.
Knowing where you have been on the web, and seeing the trends for today will guide you in the right path for tomorrow!