When investors compare online stock brokers and broker fees, it can be a maddening task. Like any stockbrokers, online brokers are still in business to make money. This means when you compare online stock brokers, investors have to remember that the brokerage firms are looking out for themselves first.

Of course, the dog-eat-dog competition that has characterized the online stock brokerage marketplace recently has generally been good for investors. Many online brokers have dropped their commissions to rock-bottom levels.  And they’ve ramped up their services and research tools dramatically. But that just means that if you aren’t careful, you could end up paying far more for the services your online broker offers than you think.

Here are the five secrets your online broker doesn’t want you to know…

Online Broker Secret #1: You may never get those discount commissions

Online stock brokers that advertise commissions of $12.99, $7 or even zero, typically reserve those commissions for certain types of trades (online), certain types of securities (stocks) and certain types of investors (active traders or those whose accounts are above a certain asset value).

Want to trade by phone? You’ll pay $34.99 for automated telephone trading at TD Ameritrade. That’s far higher than the $9.99 commission TD Ameritrade advertises. To qualify for that commission, you’ll have to trade online.

Like to hear a voice on the phone when you give your buy or sell orders? Broker-assisted trades will set you back $27 per trade at Scottrade, not the $7 commission Scottrade advertises.

Prefer trading options? You won’t get those 10 free trades per month offered by Zecco. To get that deal, you’d have to trade stocks. For options, you’ll pay $4.50 plus 50 cents per options contract.

And some brokers make the hurdles even higher.

To qualify for the best commissions at Fidelity, you have to have $1 million in assets.

At E*trade, you’ll have to make at least 1,500 trades per quarter — far more than many investment experts suggest is wise.

Online Broker Secret #2: Even the best commissions can cost you

Commissions are only one way online brokers make money. Fees are another source of revenue for them.

And depending on how big your account is, how frequently you trade, what type of account you have and how much of your investing business you want to do online, the fees you pay could even surpass the commissions.

Before you open a new account with an online broker, get a breakdown of all the fees you may be charged.

Pay close attention to whether or not the broker charges annual maintenance fees, fees for inactivity, fees if your account drops below a certain asset level, fees to host your IRA, fees to close your IRA, fees for paper statements, and confirmations and fees to transfer your account to another broker.

Online Broker Secret #3: Comparison shopping based on price is difficult

Rare is the online broker with a simple, straightforward fee structure.

Not only do online brokers often charge more for broker-assisted trades, mutual fund trades and options trades, but some also charge more when you buy a large block of shares (typically 1,000 or more).

Fidelity, for example, offers its best customers commissions of $8 to $10.95. But if you don’t make at least 36 trades per year and have $25,000 in assets with Fidelity, you’ll have to pay $19.95 plus 1.5 cents for every share over 1,000.

That means purchasing 5,000 shares of stock will cost you $79.95 in commissions at Fidelity — not the advertised $8 to $10.95.

Online Broker Secret #4: Expect to pay for human contact

…and even then, you may not be able to get anyone on the phone.

While some online brokers are certainly very responsive to customer phone calls, emails and live chat questions, others offer limited access to live help, at best.

Some don’t even offer broker-assisted trading by phone, so if the web site is down, or your own Internet service is out, you’re out of luck.

Before you open a new account with an online broker, ask about alternatives to trading online.

Find out what the live customer service hours are. And test-drive the broker’s customer service. Send an email, call, test the live chat feature. Note how quickly your call or email is answered as well as the quality of the response.

Online Broker Secret #5: If you’re worth it, brokers will negotiate

Stockbrokers have always given high-asset-value accounts perks. And many of today’s online brokers are no different.

Some will negotiate commissions with you if you have substantial assets or if you trade very frequently. Others will negotiate fees.

When asked whether he’d consider waiving Zecco’s $30 annual IRA fee, Zecco President Michael Feser said, “We’ll always work with a customer. I’ll do what it takes to keep their business.”

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