American Express Co reported a whopping 21% rise in quarterly profit on Wednesday.<br />A strengthening U.S. economy drew in more customers and encouraged higher credit card spending.<br />Reuters reports net income rose to $1.62 billion, or $1.84 per share, in the second quarter.<br />That's up from $1.34 billion, or $1.47 per share, a year earlier.<br />Total revenue, net of interest expense, climbed 9 percent to $10 billion. <br />
