The three secrets of business analytics (no rocket science here)

I think it depends what you're measuring and how different your key metrics are. I do a number of bespoke projects with clients looking to better understand they was different aspects- like the help desk, sales, and training sections- impact on each other. That's tough to find "off the shelf".

(I wrote the original post)

There are tons of great third-party tools for data collection, and in some cases, you'll be hard pressed to come up with a better home-grown alternative (you probably won't write your own Google Analytics/Clicky/etc alternative). In some cases, even when there is a third-party tool available, it makes sense to write your own - the costs for some of the per-datapoint tools can get quite high, and you don't always want to be sending a high volume of data to a remote server (I'm a huge fan of things like statsd, which are very lightweight).

Where there aren't good third party tools is in pulling together all of your data sources in a way that you can easily compare them against each other. This is hard to do, since everything has a different API, but I find to be really valuable when you can get it done.