It's not a book; Britannica is a website now. They might sell you some books if you try, but that's not what they are editing for or producing. Britannica's ad

It's not a book; Britannica is a website now. They might sell you some books if you try, but that's not what they are editing for or producing. Britannica's advantage is that it's written by experts and edited by professionals. If I want knowledge - for business, for my health, for legal, accounting, car repair, IT - I ask experts. There are downsides - it's not nearly as large as Wikipedia, and it doesn't engage the crowd. But I know someone with expertise verified the facts, and the completeness, correctness, and consistency (the three C's of accuracy) of each article.