Ron Shaw's advice: Don't tell your customers this.
When a guy's printer type began to grow faint, he called a local repair shop where a friendly man informed him that the printer probably needed only to be cleaned. Because the store charged $50 for such cleanings, he told him he might be better off reading the printer's manual and trying the job himself.
Pleasantly surprised by his candor, he asked, 'Does your boss know that you discourage business?'
'Actually, it's my boss's idea,' the employee replied sheepishly. 'We usually make more money on repairs if we let people try to fix things themselves first.'