If you've ever seen an electrical technician or engineer diagnosing a device with an oscilloscope, perhaps you know what I mean. I have a regular multitester - it shows static voltage, but it doesn't really show what is going on. With a varying voltage, the oscilloscope shows what's really happening - how the circuit is truly responding. This is what continuous integration does. We probe with intermittent unit tests, and assume they are characteristic of real behavior. But running the tests all the time shows the whole story. You can find out a lot of scary stuff with continuous testing - the only thing scarier is your customer find the same stuff out.