The Primary objective of a business website is to attract potential buyers and convert them into paying customers. Relevant keywords allow you to fulfil this primary objective. They help you attract relevant traffic that want to buy the types of products you have to offer, however, the more relevant keywords that you rank well for, the more business you will do. By effectively expanding your keyword lists, you expand the potential market for your business.

There are two fundamental ways of expanding your keyword lists:

* Long tail keywords that give you depth and allow you to dominate a particular market - so, moving from 'chocolate' to 'chocolate gifts' to 'corporate chocolate gifts'. These long tailed keywords tend to have a smaller advertiser competition, therefore you get a better PPC price, also, you dominate that specific niche market.

* Related keywords that allow you to broaden the range of market sectors that you can target. So, if you're selling gourmet chocolate, you may find opportunities in related keywords such as 'truffles', 'fudge' or 'luxury foods'. Related keywords can make you aware of markets that you might now have considered. So in building your online business, you need to make sure you have an effective sales process in place. Do that and you will have real benefit from expanding your keyword lists.

You need to convert people who arrive at your website into paying customers. If you don't do that, then it doesn't matter how extensive you keyword research is, or how effective your optimization efforts are in drawing new visitors to your website. If you can't convert a visitor into a customer then your efforts will be doomed to failure.

Only when you have got an effective sales process can you get the real benefit from expanding your keyword lists. And when you have that sales process in place, like any business you will want to expand. You could add new product lines, associated products and other ways to expand your potential income from each of the customers you attract.

However, before you embark on the path of product development you need to be sure that you are getting maximum return from what you have already. Let's suppose you've got a website that performs well - you get 100,000 unique visitors per month and you have a conversion rate of 3%. That equates to 3,000 paying customers per month. Not a bad business situation to be in.

Now look at your log files. From these you see that 30% of your traffic comes from search engines. Dig a little deeper and you find that 80% of this comes from around 20 good keywords. Here's a quick calculation of what this means:

* 30% of your traffic comes from search engines so that's 30,000 unique visitors per month. 80% of these come from your top 20 keywords - that's 24,000 per month.

* With a conversion rate of 3%, those 20 keywords bring you 720 paying customers every month. Now, if you could find another 20 keywords that perform just as well, then you could add another 720 customers, giving you a total of 3,720 customers per month - an increase of 24%.

And if you could achieve this growth once, could you do it again? Of course, the answer to that depends on the potential in your marketplace but the underlying principle is that good keywords will bring additional revenue to your website and you really can't get too many of them.