Any honest assessment of Google (Nasdaq: GOOG) needs to take failure into account. Notebook? Dead. Lively? Also dead. Dodgeball? Acquired and then killed, leading the service’s creators to develop Foursquare. The list goes on, and on, and on.

With this history, why should anyone think the new Google+ social-networking service will find users at a time when Facebook is preparing to go public at what could be a $100 billion valuation? LinkedIn (NYSE: LNKD), Twitter, and Renren (NYSE: RENN) in China -- all these services and others do what Google+ purports to do.

Or do they?
Fine-grained control is where Google+ differs. Using a concept called “Circles,” users of the service define who sees what when they post. Want to broadcast like Twitter? Fine. Prefer to limit sharing to just friends and family a la Facebook’s groups? Also fine.

There’s more to Google+ than circles, of course. But this essential element -- handing fine-grained distribution control to users -- mixed with a hint of exclusivity has enticed a growing number of users to try the service. And that’s when the fun begins.

G+ is remarkably flexible. Posts can be edited, limited, pulled, or re-shared. Streams can be sharpened by circles while add-ons provide richness. “Sparks” add what amount to RSS feeds. “Hangouts” offer a compelling enough group video-chat service that Facebook teamed with Skype in response. A mobile edition of G+ includes the ability to check in a la Foursquare or Facebook and adds “Huddle,” a group-messaging service for arranging meet-ups.

Anatomy of an addiction
Each of these features is useful in its own way. But what users really appear to love are the hidden tricks for enhancing G+. They’ve even written a love letter in the form of a user guide, developed collaboratively inside Google Docs. Find it here.

I can’t say for sure how long it took to write, but the guide is chock-full of tips. Participants are clearly enjoying the element of discovery the system’s designers cooked into G+. That’s a sharp contrast to Buzz, which was much more about broadcasting than serious discovery and playfulness. Google+ is more ... Google-y.

But don’t take my word for it. Here’s a list of some of the guide’s more interesting tips:

  1. Formatting changes. Unlike Twitter and Facebook, G+ has commands for adding formatting to posts. Surround text with asterisks to make it bold. Use underlines to create italics.
  2. Send an email. Say you’ve found a post you’d like to share with someone not on G+. You can email them directly using the field typically reserved for circles. Just eliminate the default circles by clicking the “x” on each one and then add your friend’s email address.
  3. Sharing across networks. Chrome offers multiple extensions for sharing with Facebook, LinkedIn, and Twitter from inside G+, making it a poor man’s TweetDeck, you might say.
  4. Staging circles. Name a circle “drafts” and leave it empty. Share with this circle each time you start a post you’d like to revisit, complete, or edit later. In this sense, G+ can be as much a blog as it is a social network.

The make-it-whatever-you-want social network
As interesting as these features are, they aren’t what make G+ the winner that Wave wasn’t. Nope, the mark of a successful product is that users make it their own, above and beyond the creator’s intended purpose. Remember, it was users, not Apple (Nasdaq: AAPL), that made the Mac a desktop-publishing platform. In social media, it was users, not Twitter, who turned the microblogger into a news service. Thanks to the Google+ guide, we know that users have their own ideas for G+, too.

Investors should love this. G+ may not be a Facebook killer, but as I’ve said before, I can see it creating serious value for the Google Apps user and threaten Microsoft’s (Nasdaq: MSFT) Office franchise in the process. Average Google users like me should also see benefits.

Here’s just one example: Each week at Motley Fool Rule Breakers, we meet for an hour via Skype to talk stock ideas. Next time, we’ll be using “Hangouts.” I believe the feature could become seriously disruptive if mixed together with Google Docs’ built-in sharing capabilities. Each meeting would include a virtual whiteboard with real-time notes and critiques. We get smarter, and so do our members.

Or maybe that’s overstating it. All I know is there’s now a massive document, built by dozens if not hundreds of people, that’s dedicated 100% to Google+ and its funky and occasionally ingenious quirks. There’s no mistaking what this means. After years of trying to get social, Google finally has a hit on its hands.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.