TV tower, Berlin
It's a very though and a good question. But it's the very basic question before every campaign or development work you do at your site. There is no reason to measure just visitors if you haven't indentified your website goals. I give you couple of good examples to pick up:
- Sales & Marketing. Direct web sales, indirect offline sales, leads or market awareness - they all got something to do with sales and every business decision maker should by now realize that people (both b2c and b2b) are using web for searching goods and services. And they are also buying...so don't be ashamed about being capitalist. Purpose of every business should be maximization of the profit and one way to do it is to grow your sales!
- Information or Persuasion. More for the public good or non-profit organizations, but also companies which somehow wan't to ignore bullet #1 and maybe for politics too.