Businesses that are looking for dozens, or even hundreds of new customers (like a cleaning service or a copier repair center) can invest heavily in printing and mailing tens of thousands of flyers in the hopes of getting a return of just a small percentage of interested customers. But for you as an independent computer consultant, the cost to embark on a large campaign where you'll print and blindly mail hundreds of flyers (especially if you're just starting a computer consulting business) would not generate the sales quickly enough to justify the large expense. Your flyer WILL be effective however if used to support your other sales efforts.
The purpose of your flyer is to get your prospective customer to take a specific, desired action. Just as with your other sales and marketing efforts, your intention is to help your target recognize that they have a problem in need of a solution and to show them how your service will solve their problem.