In 2015 the U.S. Naval Academy reinstated training in how to navigate using a sextant, a device dating back to around 1730.

Why learn how to use an obsolete device like this, when GPS navigation is so much more reliable?

It turns out the signals from our GPS satellites are relatively weak by the time they hit the earth. If you can drown out the true–but weak–signal with the right kind of noise, your computer can be fooled into erroneously calculating your position.

If you’re reasonably clever and have about $1,000, you can do it too.

Let’s bring this back to marketing. How can you be sure that your marketing navigation system is picking up the true signal, which can be very weak in these days of bots, fake traffic, and across billions of rows of impression data?

The answer is to check your marketing whiffletree (you’ve built one, right?) and see if the answers make sense. If you get any strange or conflicting data, it’s time to figure out why the data doesn’t agree. Is it the signals are wrong? Or are they being interpreted incorrectly?

You can ground your marketing campaigns on a reef of woe if you don’t know where you are. Make sure your captain (CMO), executive officer (VP of marketing) or somebody knows how to do things the old-fashioned way. And make sure you check with them!

Takeaway: Don’t just trust what the computers and models say. Check the results with an offline tool or just old-fashioned logic. Then act. And win.