Xero says it now has more than 400,000 users of its low-cost cloud-based accounting application. That means it has added 29,000 since the second quarter ended on September 30, an increase of 7.8 percent. By comparison, Intuit had 739,000 QuickBooks Online users when its first quarter ended on October 31, up from 683,000 when the fourth quarter ended on July 31, an 8.3-percent increase.