The old adage that you must rank only for one or two keywords is definitely NOT sacrosanct.

For most of us, ranking for keywords on our websites means that we pick just a tiny handful of keywords and then decide that these are the few we’ll repeatedly target. For example, I recently worked with a client to redevelop his website and he wanted to focus almost exclusively on windproof umbrellas as a keyword (which is after all what his site was about).
However, if you really want to increase the traffic to your website, one of the best ways to do it is to look for additional, related keywords which you can rank for.
Obviously you don’t want to end up with a situation where the umbrella site I mentioned above is suddenly getting hit up by people looking to learn about Omaha steak houses, but there would be nothing wrong at all with him ranking for other weather related gear, such as rain slickers, galoshes and even parkas if we wanted to expand further.
The point is that by expanding into related keywords, you may well get more hits on your site from customers who are interested in what you have to sell but may have been searching for some other item prior to stumbling on your site (again, it’s conceivable that our friend above may find customers who were looking for rain slickers would also want an umbrella).

Finding the Right Keywords

Ideally, you should consider using software to do this. I did a review here a while back of two of the best choices, Market Samurai and Brad Callen’s Niche Finder. Both are good though I personally use Niche finder for my own needs. You can also use the Adwords tool to find related keywords, but the two products above are better designed for finding just the right keywords.
In essence, you want to look both for long tail keywords and related keywords to your original keyword. This would mean again with the example above that we might be looking for “best windproof umbrellas for London weather” or “rain slickers” as possible topics that people might be looking for. The software products above will help you to find just what you need.

One Method to Rank

brain surgery

Don’t worry — this isn’t brain surgery at all. It’s really easy to do.

There are several possible ways to rank for these related and long tail keywords. Probably the easiest though is to simply make use of them as secondary pieces in your writing. So for example, you might primarily be targeting the keyword “windproof umbrellas,” but you could then go ahead and mention words like “galoshes” and “rain slickers” as part of what you write.
The key here as with any use of keywords is to make it all look natural. The worst thing that you can possibly do if you want to rank for more keywords is to simply create a pile of junk which doesn’t make any sense but which has all the right keywords in it. Instead, look for places that you can naturally insert these keywords.
You can even create a spreadsheet which includes the primary keyword that you wanted to rank for and then also include the secondary and tertiary keywords that you want to use. Then, simply refer to your spreadsheet periodically while you are writing content for your site (or send it to your content writer who can do the same thing) and try to include as many of these extra keywords as you can.

Follow the Authority Site Model

Another great way and probably the very best way to actually rank for five times more keywords than you currently rank for is to simply follow the model of an authority website. In essence, when you do this, what you want to do is to create lots and lots of quality content which will attract plenty of links. You can then create several different sections and subsections within your website and allow your customers to see all these things.
A good example of this would be one of the major news sites like MSN News and the like. However, even if you don’t want to create the kind of site which will include constant updates on an hourly basis, you can still vary your content more and over time you will come to rank for many more keywords and you will have the bonus of being seen as an authority website.

Vary Your Anchor Text

Hell's utensils

Sure you might prefer to rank for pitchforks. But sometimes, you can vary your anchor text and rank for spoons and knives too…

Finally, probably the simplest and frankly one of the best ways to rank for many more keywords is to simply vary your anchor text more. This will actually solve two different problems for you. First and foremost, it will allow you to rank highly for many more keywords because you don’t have everything concentrated on a single word.
Second and even more importantly, you will effectively be helping your site to avoid the Penguin update because your links will appear much more natural since they have so many different kinds of keywords attached to them.