Here are five key performance indicators (KPIs) to consider when looking at your Web site:
Conversion Rate: How many people "convert?" A conversion can be ordering wine, joining your wine club, signing up for your e-mail newsletter, calling the winery, subscribing to your blog, etc. You get to decide.
Average Order Size: Pretty straightforward, and one which you want to watch over time.
Days & Visits Until Purchase: How much time, and how many interactions does it take for someone to finally decide to buy from you? This can be surprising.
- Visitor Loyalty and Recency: How often do people return to your site?
Task Completion Rate: I support this one whole-heartedly. It doesn't matter if someone visits your site if they can't accomplish what they came to do. Hard to measure, but well worth it.
Read lots more details in this post from the author of Web Analytics: an hour a day. He offers a sixth KPI and some rules for using them effectively. I really like what he has to say about Task Completion Rate.