The Arlo Audio Doorbell ($79 at Amazon) costs $80. I know it sounds like a steal since most smart doorbells cost about $200, but limited features and some unexpected extra costs ultimately make it hard to recommend to most. 

As its name suggests, the Audio Doorbell is an audio-only device; there's no built-in camera. You'll still get a push alert when the doorbell's motion sensor detects activity -- or if someone rings the bell -- but you can only speak to them. You can't see them.

You have to buy a separate Arlo, Arlo Pro ($180 at Amazon) or Arlo Pro 2 ($168 at Amazon) cam to add that video component and one Pro 2 camera costs $220. And, even if you don't want an Arlo camera to accompany your Audio Doorbell, the $80 Arlo Base Station is required for the buzzer to work. The doorbell and the Base Station alone take the price up to $160; add in the camera and it's a whopping $380.

The price gets even higher if you decide to run your doorbell on two AA batteries rather than the hardwired option, since you'd need the $50 Arlo Chime to hear your doorbell ring like it would if you had a mechanical or digital doorbell chime already in your home. The Chime accessory moves the price tag over $400 to get the functionality of one regular smart doorbell. (Again, most connected buzzers cost about $200 total.)

If you already use Arlo cameras and the base station that comes with them, you'd only need the doorbell (and possibly the Chime accessory) to have a fully functioning smart doorbell. That might be worthwhile, especially since the doorbell itself and the related Arlo app perform just fine. 

Everyone else should look for an all-in-one smart doorbell from competitors like Nest, Ring, August or SkyBell.

Setting up the Arlo Audio Doorbell is very simple. First download the Arlo app on your Android or iOS device and create an account. Click on the "Add New Device" button and follow the tutorial. 

At minimum you'll need the $80 Arlo Audio Doorbell and the $80 Arlo Base Station to use this smart buzzer. As you can see in the screenshot below, the app takes you from one step to the next fairly seamlessly. In addition to the doorbell and the Base Station, I also added in an Arlo Pro 2 camera and an Arlo Chime accessory.