I have a filter on my gmail so my phone plays the coin sound from Super Mario Bros. every time I get a Paypal/Etsy/Ebay/Amazon payment. It's quite satisfying to hear that throughout the day.
A friend of mine set up IFTTT so his phone would play a "ka-tching" sound every time someone paid for a premium account for his startup. The novelty never seemed to wear off.
Can you elaborate? I've been looking for a way to do this on an iPhone.
You can use Pushover for that: https://pushover.net/
Just install the client on your phone and ping the API on each sale.