google+That’s right, there’s another single sign-in platform in town.

Google recently announced its new Google+ Sign-In platform during the Google Developers Live stream. I’m all for minimal user names and passwords so I think this single sign on might be a big Google+ win, but only if it can compete with the existing Facebook and Twitter sign-in platforms.

Not only does the new sign-in system provide ease of use for site and app users, it also has huge potential to facilitate consumer interaction, expand online communities and increase mobile app downloads for businesses and web developers.

So how does Google+ Sign-In really work and how could it possibly increase your online consumer engagement and inbound leads? Here’s a down and dirty explanation of the new features from Tuesday’s nearly 40-minute Google announcement.

Google’s New Shiny Red Button — What, Where and When?

The Google+ Sign-In feature is represented by a shiny red “Sign in with Google” button. Supported on the Web as well as Android and iOS devices, the feature will allow users to sign into websites and mobile apps using their Google accounts rather than having to create a new user name and password.

Users can then choose what information the site or app will have access to and which circles will be able to view their activity. The visual authentication and choices are almost identical to Facebook’s longstanding sign-in option but I have to give a +1 to Google: the red button seemed to catch my eye a little more.

Google plans to roll out the functionality globally in the next few days, but for now, the initial Google+ sign-in launch is currently limited to 10 partner sites: Flixter, the Fancy, Shazam, USA Today, The Guardian, Banjo, Beautylish, Fitbit, OpenTable and TuneIn Radio. You can head on over to those sites right now to do a little testing or discover how they’re using Google+ Sign-In first hand by checking out case studies.

I spoke to Ted Kemp, one of the developers at Maxwell Systems, who told me that he’s really excited about the global release of the Google+ sign-in. “We’re eager to integrate the social elements of Google+ with our e-commerce system. Users could buy our software and automatically share the purchase, or even write a review that would get posted on their profile. It’s definitely going to be a cool new feature.”

Buy, Listen, Vote or Review — You Choose Your Users’ Action

Once a user has logged onto your website or mobile app through Google, interactive sharing allows them to share information from your site with their friends, family and professional connections via their Google+ circles. This is where the Google+ sign-in offers a bit more interactivity than Facebook’s sole “share” button: Developers will be able to choose from more than 100 verbs to represent a call-to-action like “buy,” “listen,” “vote,” or “review.”

Interactive sharing will also allow developers to customize the text in a user’s post. Unlike the empty Facebook “share” box users are accustomed to, the Google+ posts will help businesses and marketers start the user’s dialog. This pre-fill text will appear as a default entry for the user. Users can then share as-is, modify the message or erase and add their own text.

Users will also be able to include another user in a share. Let’s say I want to share a new product review with my co-worker. With this new sharing system, I can include her on the share and she’ll be notified through her Google+ notifications across the Web. Even better, if she has Google notification emails enabled, she’ll get the message delivered straight to her inbox. This peer-to-peer sharing will also encourage people to use your websites and apps, since they will likely interact with a post shared to them from someone they trust.

Go Anti-Spam With Selective News Stream Sharing

Much like interactive sharing, there’s also selective sharing. One of Google’s main fears while developing this new platform was the potential of news stream spam. Think about it, how many times have you heard people complain about all the game, website and online streaming spam on the Facebook news feed? Fortunately, with selective sharing, users can easily opt for content not to be automatically shared within the new stream but instead only on their user profiles.

Once a piece of information is shared on a user profile, the user can then determine when and if they want to share the post with their circles. For example, if I click “listen” to a song through an app, I can choose to have that record only appear on my user profile. That way, I can keep a record of the awesome new song I discovered and maybe share it with my friends at a later date.

Instantaneous Android App Installs

Last, but most certainly not least, is the instantaneous application installation available using Google+ Sign-In. If a user visits your site on the computer, and you have an Android app, the Google+ sign-in platform will automatically ask the user to install the app (if they don’t have it already). If the user chooses to install the app, it will begin download without the user even touching the device.

I think with these instant app installs, multiple sharing options and wide range of developer customizations, Google+ Sign-In just might have a shot against Facebook and Twitter sign-ins and shares.

What do you think — is Google on to something here or is it stepping into an overcrowded market?

By Adrienne Erin