…and do I need one in principle?
For the second question, not necessarily, but let’s get to the definition first.

Normally, landing pages are launched separately from your home page to promote something specific, like the launch of a new course (that you want people to click through and pay for), the launch of a new book (that you want people to click through and pay for), the launch of a new seminar (that you want people to click through and sign up for). You have a specific link for this that goes into your ad or promotion copy (like an email or social media post, etc.).
Note the common denominator of “click through and [take action].” This aspect is what makes this page different from your home page or other pages on your site. Those tend to have a menu of options that take you away from the page or even the site. Or, they have a set of panels or widget spaces that offer options to go find out more and that take you away from the page or even the site (think social media links, for example).
A landing page layout gets rid of all those distractions and keeps the person on that page until they make a final choice to click through on the action step you want them to make. You’ll notice if you’ve been to these pages that they have no menu or other links to anywhere, except regular reminders as you scroll down to click through to purchase or sign up for that one thing (sometimes people get carried away with the reminders). The reminders serve the marketing purpose that email reminders do for a webinar someone is promoting to you via email; it is true that most folks sign up at the “last call” before the event starts, so reminders do work, and that’s also true on a landing page.
Most WordPress themes allow you to choose “landing page” as a layout option, which is nice because it automatically gets rid of your menus and footer area, and leaves you with just your basic branded layout and room to write content and make links to that one follow-on page. A Google search also produced thousands of examples from places promoting templates for landing pages. No wonder it’s such a buzz term! Still, the content itself is what sells more than the template, but you are in charge of that part. 🙂
Home Page as Landing Page
So, great. You can create a landing page for something specific and have a better chance to keep people on your page to take a specific action. But this layout is normally reserved for an event (launch of something).
Lately, I’ve been seeing and hearing advice from marketers (particularly Chris Brogan at Owner Media) about making one’s home page on their website look more like a landing page. And I’m seeing the potential advantages.
After you do your content strategy and decide what you want your prospective customer to do on your home page (make an appointment, browse the shop, contact you directly), it’s likely a good idea not to make it too easy to leave. That doesn’t mean you provide no links away from your site or to more-info pages that don’t ask the viewer to make contact, but placement can be important in not causing distractions that aren’t good for your business.
That said, I’m not talking about websites that have ads here. I don’t favor that approach because of the distraction, but if you have a sizable audience already, it can be part of income generation.
You can use a landing page philosophy to enhance the focus of your visitors on your home page, though. This philosophy goes hand-in-hand with simplicity of design, so I like it for that reason as well.
It doesn’t mean that you start putting action steps in bold blue color at huge font sizes, though. I still want everything to look balanced and in line with my theme. What I’ve done with my site’s home page here is to keep the menu to a minimum (About, Blog, Contact), and to make the first actions ones that lead to a connection to talk about a prospective client’s web design needs. The top button goes to a page with a video and a short bit of info followed by two options to connect, and the two choices just below that go to an option to connect directly or to buy something.
I leave browsing my portfolio further down, and don’t have a sampling of my blog posts on the front page. Instead, at the bottom, a reminder to connect. And the footer is the first place where there’s an option to leave the site altogether (social media links).
I haven’t tested this design against more traditional ones that provide more places to go, but I’m thinking just based on common sense that fewer distraction links will be better for business.
Let me know what you’re looking to do to simplify and focus your website design. I’d also love to hear of any tips and tricks that have worked best for your biz.