Exploring Profit Margins: Are Wired Telecom and Oil Support Services the Most Lucrative Small Businesses?

Wired Telecommunication Carriers

Average Pretax Margin: 10.1%

This industry comprises operators of, or suppliers to, transmission facilities for voice, data, text, sound, and video using wired telecommunications. Hey, it's a wired world.

Support Activities for Oil and Gas Operations

Average Pretax Margin: 10.3%

Includes contract outfits that perform a variety of services, on a fee basis, for oil and gas operations (except site preparation and related construction activities). Services include, among other things: exploration (except geophysical surveying and mapping); excavating slush pits and cellars; well surveying; cementing, cleaning, bailing, and chemically treating wells. Dirty work, but someone has to do it.

3. Diagnostic Imaging Centers
Average Pretax Margin: 10.5%
Small operators may have difficulty raising the funds to buy expensive equipment; once it's installed, however, economies of scale begin to take effect. Depending on the type of lab, the marginal cost of conducting "one more" test—thanks to typically lean staffing—can be very small.

4. Investment Advice
Average Pretax Margin: 11%
These are financial planners who don't have the authority to execute trades. Few things are as opaque as fees for financial services—which is probably why this industry makes our list.