Are you ready for commission-free stock trades, my penny-pinching friend? We'll find out next month when nascent financial site promises to launch a fee-free trading platform. This could be revolutionary. Then again, this could also be a non-event.

Thanks to the arrival of online discount brokerage specialists like Ameritrade (NASDAQ:AMTD), Charles Schwab (NASDAQ:SCHW), and E*Trade (NYSE:ET), no one is really paying $40 or more for modest transactions like they once used to. The comparison table at our Broker Center features four sponsor brokers that will let you get in or out of a stock for less than $10 apiece.

Yet there are few words as powerful as "free." Even Richie Rich over there -- using dollar bills to light his stogie -- can't resist the free cheese sample at the gourmet supermarket. That makes it safe to say that Zecco has the perfect worm on the hook leading to the Oct. 9 debut of its commission-free trading site. Will investors bite?

There's no free lunch, unless I'm treating
The Zecco model is somewhat sound. The site is already plastered with text and graphical banner ads using Google's (NASDAQ:GOOG) AdSense program. As the theory goes, by providing financial news, blogs, and forums, investors may congregate near their free trade hub. Advertising revenue should help offset Zecco's actual outlay to complete the trades.

That isn't the only way that Zecco stands to make money off commission-free trading, of course. Brokerages can make a decent living off the interest spread being paid on idle cash deposits, as well as benefiting from higher margin rates. In the past, brokerages have also been able to make a little money by either making a market in certain stocks or receiving payments for order flow.

In short, there are several revenue streams for Zecco to paddle above and beyond contextual marketing ads from Google. The company is headed up by a former vice president out of Merrill Lynch (NYSE:MER), so I'm sure it has as many oars as it can muster already in the water.

In a perfect world, this becomes the freebie that emerges as a disruptive technology. Have you seen what Craigslist has done to newspaper classified ads? Are you seeing what Zillow is doing in residential real estate?

There's a fatal flaw lurking in the Zecco model, though. That juicy bait on the hook? Let's play a little game theory. Who are the investors likely to trade with Zecco? Think about that for a second, and I'll meet you at the other end of the following subheader.

Buy, sell, or hold on to those gift horses
Over at Ameritrade, the company closed out its latest quarter with $255 billion in assets and 6.1 million accounts. That means that the average account is worth in the ballpark of $40,000. So here's the kicker: how many people do you think will sign over a check for $40,000 made payable to a brand new site with a doozy of a magnetic gimmick yet without a proven history?

My guess is that the high-rollers and even the medium-sized investors will stay away at first. With a plethora of time-tested deep discount brokers out there, the difference between nil and $7 may seem to be little more than a rounding error to them. If that's so, they may never come around.

That leaves Zecco attracting small -- perhaps novice -- investors. There's no shame in attracting a curious market watcher with just a few hundred bucks to throw at the market. In fact, that's always cool, because people have to start somewhere. The problem is that small accounts won't generate a whole lot of spread revenue. You'll also find some thrifty speculators hyperactively trading in odd lot increments, and they'll likely be more trouble than they're worth.

But what about the ad-supported model? Aren't all eyeballs the same? Of course not. Looking through the Google ads being served, most of them are for rival discount brokers. Are folks really going to be lured into clicking an ad for rock-bottom commissions when they're already trading for free? Nope. That's like your girlfriend Angelina Jolie -- or your boyfriend Brad Pitt -- handing you a dating personals circular in the morning. You can't beat nil, right?

Unfortunately, you can't. The quality of the leads that are ultimately generated may not be all that appealing to the advertiser either. Zecco can always turn to impression-based ads to make up for the indifference in volume, but it's definitely not the ideal solution.

At least it swung away
In the end, at least I can applaud the spirit, the innovation, and the will to stand out in a crowd. I think the model's got holes -- some of them big enough to drive through -- but if it takes off even a little bit, it can send ripples through the brokerage industry. Which bears watching.

That's the kind of seismic activity that we track with gusto over at the Motley Fool Rule Breakers growth stock newsletter service. Some of the best companies are born in a cloud of naysayers.

So best wishes to you, Zecco. Here's hoping that in offering up a free platform for investors, you don't wind up with more than you bargained for.

Longtime Fool contributor Rick Munarriz has been trading exclusively through discount brokers since 1990, but he does not own shares in any of the companies in this story. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. Charles Schwab is a Motley Fool Stock Advisor pick. The Fool has a disclosure policy.