Both advertising and publicity are about creating top of mind awarenes--staying in front of your prospective readers/users/customers on a consistent basis so that, when they're ready to buy whatever it is you're selling, they'll think of you ahead of your competitors. The difference is this: whereas advertising is you talking about how great your book, product, or service is, publicity is a respected member of the media plugging you, your book, product, or service. Publicity is gold for all entrepreneurs because it's like adding lighter fluid to your advertising campaign to really fuel that flame and make it even brighter.
So how do you get publicity? Here are two ways (and I invite others to post here to add other possible ways to this list, too).
1. Traditional book reviews are a valuable form of publicity, so I always recommend to authors that they should send either a digital or physical copy of their latest book to all relevant book reviewers in their targeted trading areas. And, when the review comes back, share it on all your social media sites. (I share mine over and over again to maintain that top of mind awareness with my readers.)
2. You can also generate publicity free of charge by writing a relevant news story for the media in your area that somehow ties into either your book or your own company. This requires a bit of ingenuity in that your story needs to relate to current events. It has to be something the public will want to read now in order for the media outlet to pick it up. But it can definitely be worth the effort for you in the long run because it can help position you as an industry expert in your field with the mainstream media while also giving you extra copy to share on all your social media platforms.
Publicity is GOLD to an author! You should definitely tie it into your current advertising efforts.
I hope you found this bit of information useful. If you have any other tips for how to garner publicity, please add them to this list. We can all help each other.