So this is how the story goes. Panic, the company behind Mac apps like Transmit and Coda, used to provide its followers with specially crafted URLs when alerting them of something new, like a software update. That way, the user can get the info with just one click.
When the Mac App Store was in beta, I was really hoping for something similar — a simple way to notify a user of an App Store update, with a link to take them to the update in one click. ~ Panic
Panic took initiative, filed a bug with Apple, and requested this one click URL feature. Before you knew it, Apple added it to the App Store a couple versions later. Isn’t that just awesome? All you’ve got to do is use the URL below.
macappstore://showUpdatesPage
So the next time you want to alert users of an update, just send them a URL that’ll open the App Store and go directly to the updates page. You can share it via a tweet, email, web page, etc. once the recipient is on a Mac with the App Store installed. Nifty, eh?
Source: Panic