system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: if black friday is all positive revenue why don't they do deals and stuff more often than once a year?

If 'being in the black' is profit for companies, why do they limit their deals to one day of the year?
gpt
Deals and discounts are usually done for two reasons.

1. To get rid of any long standing inventory to free-up room for new orders

2. In anticipation of high volumes of demand (surge in amount of customers)

When demand is expected to be extremely high, companies can afford to mark down items and offer sales, the minimal loss in revenue from marking down products is in theory supposed to be easily made up by the added amount of revenue the company will receive from the increase in demand.

Companies aren't usually only striving for one of the above reasons, Black Friday is inherently a combination of both. Stores experience large surges in the amount of shoppers, so they start off by marking down the prices on inventory which they are trying to get rid of first. Usually the items marked down in price the most are items which have been on the shelves for quite sometimes, or are items which are being replaced by newer models (or seasonal). 

Deals similar to Black Friday aren't done other times during the year, due to the cyclical nature of retail shopping. It is much more difficult to sell products like televisions or other electronics during the year as compared with the holiday season. Some companies in fact lose a good amount of money maintaining their inventory during the year, only to regain all the lost revenue during the holiday season due to the increase in consumer demand. 

TL:DR

Giving discounts is not cost effective unless there is an increase in overall consumer demand for the products you are selling during that time period.