Black Friday saw long lines at Best Buy, Walmart and other retailers. One other business sector stayed swamped that many did not think of: gun dealers. The FBI reported their division that does background checks for gun purchases had to endure 17 work days to keep up with gun purchases on Friday. Here is a report from CNN:

The busiest shopping day of the year also saw a major boom for gun sales, with the federal background check system setting a record of more than 175,000 background checks Friday, according to the FBI.
The staggering number of checks — an average of almost three per second, nearly three times the daily average — falls on the shoulders of 600 FBI and contract call center employees who will endure 17-hour workdays in an attempt to complete the background reviews in three business days, as required by law, FBI spokesman Stephen Fischer said. “Traditionally, Black Friday is one of our busiest days for transaction volume,” Fischer said.

An average of three background checks happened every second. Here is some information on how background checks get denied and some stats on that.

Overall, about 186,000 background checks a year cannot be completed, according to the FBI. It’s difficult to know exactly how many gun sales are authorized from that number because whether to make the sale is ultimately in the hands of the shop owner. Last year, the agency completed 21 million background checks, and about 1.1% of those purchases were denied, the agency said. Firearm background checks have doubled from the more than 9 million conducted when the system was implemented in 1999.
Ten factors can disqualify a purchase: felony conviction, arrest warrant, documented drug problem, mental illness, undocumented immigration status, dishonorable military discharge, renunciation of U.S. citizenship, restraining order, history of domestic violence or indictment for any crime punishable by longer than one year of prison.