Ecommerce, with leading the charge, has already decimated lingering brick-and-mortar retail stores that sell electronics and tech widgets. Now, with its new Amazon Dash gadget, the world's largest online retailer is signaling it's serious about going after your grocery store, too.

Groceries in a Dash

To make online grocery shopping as easy as possible, Amazon recently unveiled a new gadget called Amazon Dash. The grocery list wand has a simple design with two buttons -- one for adding an item by voice search and one for scanning the barcode of whatever item you're about to run out of. It's WiFi enabled and hooks up with your Amazon Fresh account to instantly add items to your grocery list -- or if you voice-in a general term, a list of specific available items that fit your description.

The gadget is clearly designed for people on-the-go, who might not have the time to sit down and come up with a grocery list in front of their computer. With Dash, Amazon wants to make grocery list-making simple and fast when you're in the kitchen and realize you're about to run out of something, and it comes with a ring so you can hang it on your fridge. A strong magnet would have been better, but I'm guessing they tried that and it wasn't feasible for some reason.

Still In Testing: Limited Availability

Most people shouldn't expect to be dashing grocery items off your list for automatic delivery from Amazon. The gadget works with Amazon Fresh, the company's grocery delivery service and app, and both are still in limited testing.

Amazon Fresh is currently only available in the San Francisco area, some parts of Southern California, and Seattle. Amazon Dash requires you to be in an Amazon Fresh location -- and even then, you can currently only get it (for free) by invite. But if you're in the right area (and have the kind of extra cash to afford groceries by delivery) and are already a part of Amazon Fresh's trial run, you can sign up for an invite here.

The Next Ecommerce Battleground?

Setting aside the fact that this is all still experimental -- with limited availability by location (and income bracket) -- Amazon is clearly signaling that they're looking for ways to make online grocery shopping a real thing.

There's still a lot to figure out beyond the consumer gadget department (How about a tablet on, or part of, the refrigerator that displays, and lets you add to, a shopping list?).

Online grocery delivery service has been tried before, as far back as the first DotCom boom, and nearly every company failed to make it economically viable. It's still too expensive, for consumers and retailers, to deliver groceries on the regular to most locations, especially in areas of less population density and affluence. A lot of infrastructure is needed to expand online grocery shopping, and even then it's still a risk.

That said, ecommerce for groceries is heating up, with Walmart continually testing and expanding delivery and pickup services for online shoppers as well. And Peapod, one of the only early grocery stores to survive this long, is also testing out mobile services for easier list-making.

The reason why Amazon and its competitors are interested in making this particular kind of retail work is simple. Grocery retail is regular, frequent, and more resilient to swings of the economic pendulum than any other type of shopping.

If ecommerce can convince people that the ease ordering groceries online is a competitive enough advantage over schlepping through the store every week, it would open up an entirely new realm of reliable, booming business. Amazon Dash is definitely one of the first attempts to do just that.