The biggest problem with advertising, in my opinion, is the fact that for something so damn expensive, it's never guaranteed to work. And if it doesn't work, then what? You'll never get back all that money and effort that went into designing the creative and purchasing media. Instead, why not invest in something you could use to market your business that is low cost, low risk, and super-versatile? Something like... a book.

I want to show you five different ways you can grow your business with a book. By the end, I think you'll agree that, in the right hands, a good book is truly the Swiss Army Knife of marketing tools.

1. Give away the ebook as a lead magnet

This is Business Book 101: in exchange for a prospect's contact details, let them download your ebook for free. Or just give away a few chapter samples. Once you have your reader's info, you can hit them up later to upsell the book, arrange a meeting, or both.

Lead magnets are not a new innovation, but they're an undoubtedly effective strategy.

2. Make it a secret advertisement

Subtlety is the name of the game here. Readers can quickly tell if you've written a book-length infomercial, so make sure your book gives them plenty of valuable information. To reinforce the connection between the book and your business, it doesn't take much more than to making sure the branding matches up. Just use your company's colors and fonts on your cover design, and every time a reader looks at your book, they'll really be looking at your ad.

3. Send a physical copy as your calling card

More so than ever, people love receiving physical objects. The next time you meet someone of interest, get their business card and surprise them by mailing a copy of your book to their office. Write a little note on the title page, and make it personal -- then stick a bookmark in that page to make sure they read it.

Sending your prospect an email is fine, but imagine the impact of a hardcover book landing with a resounding thud on their desk. This is not cheap, but it is a proven way to: a) get people's attention; and b) let them know that you're the business.

Note: Never give someone a signed copy of your own book for their birthday, anniversary, leaving party, or bar mitzvah. Not unless you want a reputation as a cheapskate narcissist.

4. Use it to get airtime and speaking gigs

If you want to get on television (or if you have a face that belongs on the radio), then a book could be the key to getting the airtime you need. Who are producers more likely to book for their segment about yoga? Some person who works at a yoga mat startup, or the author of Salute the Sun: Yoga's New Dawn, a thrilling look at America's fastest-growing pastime?

Create a press release and start strategically targeting the channels and stations favored by your target audience. If you've got the budget for it, hire a PR agency with experience of getting clients on the air.

While you're at it, don't forget about speaking opportunities. They're a lucrative side gig, and as an author, you'll have an instant level of authority that puts you at a significant advantage over your competitors. So go out and start booking spots at those conferences.

5. A quick refresh will give you the same benefits all over again

Barring a revolution in your industry that renders your entire book obsolete, it's easy to refresh the content and retain its relevance. Add a few new chapters and you suddenly have the 'second edition' of your book, which makes it sound like the first edition was a runaway success.

If something happens to your business or you decide to move on to greener pastures, you can always take your book with you. Slap on a new title, give it a new cover, and add a new chapter: suddenly you can start all over again, attracting new leads, sending it out as a calling card, and booking more speaking gigs.

But what if you haven't written a book, or have no interest or talent for it, don't let that stop you? Don't worry: just outsource it. There are easy ways to find ghostwriters who have written books for successful entrepreneurs, VCs and corporate titans -- who can now do the same for you.

Handled the right way, your book (or series of books) will take pride of place in your toolbelt. It will be an ingrained part of your business identity, giving you to power to stand out from the crowd, and get results from your marketing efforts. With your book firing on all cylinders, you'll wonder why you ever considered paying for brand advertising.