In the US some organizations pay weekly, some bi-weekly (26 times a year), some semi-monthly (24 times a year) and some even monthly. If any one of those is your organization's standard, your payroll's systems are set up that way and the "overhead" is built into your standard procedures.

The article emphasizes "this week" not because the USPS pays weekly, but because Friday of this past week was the standard bi-weekly payday.