February 17, 2010 โ If a book is worth reading, it's worth buying too.
If you're reading a book primarily to gain value from it(as opposed to reading it for pleasure) you should always buy it unless it's a bad book.
The amount of value you can get from a book varies wildly. Most books are worthless. Some can change your life. For simplicity, let's say the value you can derive from any one book varies from 1 cent to $100,000(there are many, many more worthless books than there are of the really valuable kind).
The cost however, does not vary as much. Books rarely cost more than 100, and generally average to about 15.
You shouldn't read a book that you think will offer you less than $100 in value. Time could be better spent reading more important books.
So let's assume you never read a book that gives you less than 100 in value. Thus, the cost of a physical copy of the book is at most 15% (using the 15 average price) of the value gained.
Would owning that book help you extract 15% more from it? It nearly always will. When you own a book, you can take it anywhere. You can mark it up. You can flip quickly through the pages. You can bookmark it. You can easily share it with a friend and then dicuss it. If these things don't help you get 15% more out of that book, I'd be very surprised.
Where it gets even more certain, is when you read a really valuable book--say a book offering $1,000 of value. Now you'd only need to get 1.5% more out of that book.
The investment in that case is a no brainer.