8 - Measuring Web Site Performance
In addition to marketing, metrics can be used to measure site performance. This is important because people have little tolerance for "wait," and you should be acutely interested in reducing it as much as possible,
Measuring Throughput
Throughput is a measure of network performance: how long does it take the data to reach the user. Some things (the speed at which your server responds, how long it takes to process a request and return data) can be controlled to some degree. Others (the speed of the network and the user's connection) cannot be controlled, but can be accommodated.
Throughput can be measured for each user, but beware of interpreting aggregate measurements. They can sometimes lead to a bad conclusion. For example, if FedEx delivers a 12 packages containing 60 CDs each in 24 hours, that doesn't mean they can deliver one package containing one CD in two minutes, though the math would suggest it's so (720 CDs in 24 hours = 1 CD in 2 minutes).
Availability
Availability measures how often a Web site is down because of server-side problems (overload). It's not really clear how this is to be assessed or measured.
Web Site Performance
Fro ma technical perspective, performance is a function of the number of visitors, the number of requests, and the time it takes to process the requests. The problems are generally insufficient memory, insufficient disk storage, and insufficient processing power.
There are some tools that will measure this from "inside the firewall," but to get a complete picture, you need to hire a service that monitors performance from outside as well.
Death by Success
A rare, happy problem: sometimes, you can launch a campaign that is so successful that your Web site is overwhelmed by the traffic you receive. There are also instances where your Web site holds up fine, but your business can't handle the orders (inventory, shipping department, etc.)
The author suggests having contingency plans to handle this, but fails to go into much detail.
Bailout Rates
The author suggests that you can measure the bailout rate (the number of people who leave before the page can finish loading) and suggests it's important, but doesn't provide much useful advice.