There are a number of differences between spread betting and traditional trading. One of these is leveraging. When a spread bet is leveraged, it allows an individual to place smaller amounts of money on the line in comparison to traditional trading. Granted, leveraged bets have a higher risk than traditional trades, but as long as the trader uses sound judgment and leverages wisely the potential for income is limitless.
A good example of this is looking at a scenario such as property investment, and assuming that there is a 1,000 pound margin; an individual could use a 10:1 gearing and gain the equivalent of 10,000 pounds worth of shares while only risking a thousand. However, in traditional share trades you would need a significantly larger portion of money to make the bet, which is one of the reasons why spread betting is so popular. Regardless of the type of market you choose to invest in, by leveraging the spreads on the market you can effectively win large sums of money while risking comparatively little. However, it is a two-way street and one of the reasons why spread betting is considered riskier than traditional forms of financial betting manoeuvres.
Beyond that, stocks are never very liquid, and spread betting is based more on the model-maker position, which allows individuals to close out positions quickly, which can help leverage the bets even further in one direction or another. However, spread betting of this form is generally reserved for veterans, not novices, so keep that in mind if you are someone just getting started.