Amazon will shut down its physical bookstore business in a massive move that could potentially put tens of thousands of books in digital limbo.

The online retailer is set to begin taking bookstores offline as part of a $5 billion investment that will be completed by the end of 2019.

The move is part of an aggressive plan to take over the bookstores of major retailers, including Barnes & Noble, Target, Walmart and the Huffington Post.

Amazon is investing more than $4 billion to buy up all bookstores in the United States and around the world.

The company has also pledged to close about 30 percent of its U.S. bookstores by the first quarter of 2021.

While the bookstore closures could mean that books aren’t available to purchase online for the first time in decades, it also will put pressure on booksellers to continue their business.

Barnes & Nobles has said it will not close its stores for several years.

Amazon CEO Jeff Bezos has said he will continue to take the bookstore business offline as long as he can, and that his company will also invest billions in other businesses, including content and delivery.

In the book business, Amazon is still trying to break into the traditional book publishing business, but the company says that its strategy is to focus on e-books, and it will continue selling traditional books.

Amazon says it will buy back about 50 percent of the physical bookstores it has closed.

The deal will cost Amazon about $3.7 billion, or about $4,500 per book.