Amazon releasing discounts across entire categories is a rare sight to see, which is why customers should take advantage whenever the online retail giant launches such a promotion.

Deals website Kinja Deals reported that such a category-wide offer is currently on in Amazon, wherein customers can purchase any physical book offered by the retailer at a discount.

Customers will be able to get a 30 percent discount off of the regular price of any book being sold by Amazon, with the maximum discount being $10. To avail the offer, customers will simply have to type in the promo code HOLIDAY30 while checking out the item.

The promotion, however, only covers physical books. The discount will not apply to audiobooks and Kindle e-books that customers may want to purchase.

The discount is still a pretty significant one though, especially for customers that have been thinking about purchasing a certain collector's edition paperback book, a hard-cover coffee book and the like.

This could be the best offer that book lovers would get during the holiday season, so it would be a waste not to use it. However, customers should choose which book to purchase carefully, as the code can only be used once for every Amazon account.

For customers that prefer consumer electronics over books, however, it would be best to check out the Cyber Monday deals of Amazon, which includes unlimited cloud storage for $5, the Kindle Fire tablet for $35 and the Amazon Echo wireless speaker and voice command device for $149.

Other Cyber Monday offers by Amazon include the Kindle Fire Kids Edition for $85, the Sony SmartBand 2 with $35 off, the Motorola Moto 360 smartwatch with $40 off, an LG 60-inch 1080p TV for less than $700, the VIZIO 54-inch 5.1 Home Theater Sound Bar for less than $300 and an Intel-powered Lenovo 2-in-1 laptop with $200 off.