Wal-Mart publicized its annual bonus program for employees for the first time in 20 years, saying that about 80% of workers in its retail stores would split more than a half-billion dollars.

Based on the number of employees Wal-Mart has overall, the average payment per employee would be $651, but Wal-Mart said that actual individual payment amounts vary. In the past, the bonus was $1,000 for full-time employees and $500 for part-time employees.

Wal-Mart spokesperson Sarah Clark said that the bonus is based on two main benchmarks: whether an employee’s store met profit and sales targets for the year and whether an employee is full time or part time.

Wal-Mart was also designating Thursday of this week as Associate Celebration Day. Many stores were hosting barbecues to celebrate, and Wal-Mart announced new programs intended to recognize service and performance.

Critics continue to say that Wal-Mart is doing too little for its employees, especially in comparison to the huge bonuses and pay packages that the company executives receive. CEO Lee Scott’s compensation for 2006 was $15.7 million, excluding restricted stock awards.