You've seen it before: investors, euphoric during a rising market, chase returns, only to bemoan their fate as the market turns. These same investors, move from one asset class to another as markets shift, searching for elusive returns instead of staying invested.

When emotions interfere with investment decisions, the portfolio suffers.

Dalbar's Quantitative Analysis of Investor Behavior Study concludes the average investor acts on emotion, resulting in returns that barely outpace inflation. The study shows the average equity investor acting alone netted an average annual return of 3.9% over a 20-year period, far below the S&P average of 11.9% enjoyed by institutional investors.

What does this mean to you? Unless you're a robot, paying brokerage commissions or a sales charge to an investment firm may prove financially beneficial in the long run.

Here's why:

• Experience

In sports, coaches rely on players with experience. Experienced players don't panic after a minor setback; nor do they get caught up in celebrating after a minor success. They are steady and reliable. Experienced investors share the same characteristics. They don't panic with every market downturn; nor do they celebrate with every little gain. They plot a steady course, making adjustments when appropriate, in order to help you achieve your goals.

Those without experience, never having seen the ups and downs of investing, allow their emotions to dictate their behavior.

• Perspective

Investment firms employ a team of professionals. The average investor employs Uncle Fred. A firm provides a group of investment analysts. The average investor provides a coin for flipping. A firm reviews your investment for consistency with your objectives. The average investor reviews horoscopes.

In short, an investment firm sees the entire picture and relies on fundamental analysis. The average investor only sees his or her small part and relies on emotional reactions to misunderstood market movements.

• Focus

Profitable investing takes time. An investment firm spends the day researching the worth of an organization in relation to its stock price. An investment firm understands trends and knows what it takes for reliable long-term results as opposed to euphoric short-term gains.

An investment firm ultimately focuses on your investment goals, and chances are, they've helped similar investors in the past.

• Insight

Global research and the ability to physically visit companies before and after investing offer insights unavailable to the average investor. Worldwide offices and access to company bankers, customers, suppliers, and industry specialists provide knowledge impossible for the average investor to posses.

An investment firm employs numerous investment professionals with access to information and the ability to make sense of it.

• Conclusion

News show pundits and Internet experts often recommend ditching your investment firm and saving the sales charge and commissions. Unless, however, you have the experience, perspective, focus, insight, and have enabled yourself to eliminate emotion from your investment decisions, a small commission might just be your best investment.