U.S. retail sales continued to weaken after peaking at 4.7 percent in June—not according to a government report, which aren't being produced during the shutdown, but to one by MasterCard's own data crunchers.
The report from MasterCard Advisors said September retail sales were up just 3 percent year-over-year, which was attributed to a significant drop-off in gasoline spending and a lack of major growth in other sectors.
The company said its SpendingPulse reports historically match Commerce Department figures with a 99.86 percent correlation.
(Read more: US small business confidence dips, but improving trend remains)
The report also found that Internet retail was up by double digits over last year, while apparel, department store, hardware, furniture and furnishing sales were all down.
The report predicted a continued government shutdown could negatively affect housing and related sectors.
—By CNBC's Matt Twomey. Follow him on Twitter @Matt_Twomey.