The results are in for the J.D. Power and Associates 2007 Online Investor Satisfaction Study. It offers insights into how many of us invest these days and which brokerages please us most.

The study's bottom line is: "Self-directed investors who make the majority of their investment decisions independent of an investment advisor are more likely to be active traders with an appetite for riskier investments compared with investors who seek financial counsel." The self-directed group isn't small, either; it makes up 56% of the online investors surveyed.

Many Motley Fool readers are likely to be self-directed, gathering investment ideas from what they read online and in print publications, along with tips from other media. Many of us start with these tips, do some additional research, and then decide.

The dark side
All that is good, but our freedom and independence can cost us, too, if we trade too frequently and too aggressively. The study finds that, among self-directed investors, 14% call themselves aggressive and 41% moderately aggressive, compared with small minorities of investors who rely on advisors for their decisions.

Many self-directed investors have, with good reason, flocked to brokerages that charge relatively little per trade. (The Motley Fool's Broker Center has a handy comparison table that shows some charging less than $10 and even as little as $5 per trade.) This makes sense. Why pay $100 or more for a trade, as you might do at some traditional full-service brokerages, when you can pay just a few dollars -- especially when you're not tapping the advice of some broker?

The downside of that is that paying so little per trade makes it very easy to trade frequently -- too frequently. Do so and your trading costs can add up. One hundred trades at $8 per trade amounts to $800.

Frequent trading also leaves you with short-term gains that are taxed at your income tax rate, not the usually lower, long-term capital gains rate. And finally, trading frequently means that you may not be giving some good investments enough of a chance to perform for you. Impatience isn't good for successful investing.

There was another interesting disclosure in the study. As brokerages of all sorts have ramped up their research offers, features, and tools, we investors have changed how we use them. In the past we might have gone to our brokerage just to place our trades, but now we often use their websites to research companies and even work on long-term financial planning.

Getting satisfaction
Here's how the study ordered various brokerages in overall customer satisfaction:

  • Scottrade
  • Vanguard
  • Schwab (NASDAQ:SCHW)
  • Fidelity
  • Sharebuilder
  • Ameriprise
  • E*Trade (NASDAQ:ETFC)
  • Merrill Lynch (NYSE:MER)
  • T. Rowe Price (NASDAQ:TROW)

Branches can matter
Here's another discovery: Investors are happier when their brokers have a branch office nearby. They tend to keep more of their money with such brokerages and are more willing to pay higher fees.

This is a good reminder that when it comes to choosing the best brokerage for yourself, there are many factors to consider. Local branches, where you can talk to company representatives face to face, are a big advantage for many. For others, though, telephone access is enough.

If you trade a lot, the commission rates will matter more. If you trade infrequently, they're much less important. If you favor mutual funds, you might be better off with a brokerage that offers easy access to thousands of funds. Look at your particular needs and preferences and then see which brokerage will serve you best.

Fool s on brokerages
Learn about brokerages at our Discount Brokers discussion board. When I popped in there recently, I found, conveniently enough, a discussion on satisfaction with brokerages.

Learn even more about the brokerage biz in these articles:

Longtime Fool contributor Selena Maranjian does not own shares of any companies mentioned in this article. Schwab is a Motley Fool Stock Advisor recommendation. Try any of our investing services free for 30 days. The Motley Fool is Fools writing for Fools.