SEO or Search Engine Optimization is the Field of Study Dedicated to Placing your Website at the Top of the Search Engines.

Your website can land at the top of the search engines by two processes:

Natural listings due to the search engines liking your webpage format and information 

-  or  by -

pay-per-click (bidding on keywords against other competitors keywords.)

Which is cheaper for your pocket book and which is more effective?

WELL...  It depends on your industry, your resources, your timeframe and your business plan.    If you're in a hurry and you have your items or services ready to sell, then by all means, design your website based on the general rules of the search engine recommendations, launch your website and begin selecting your keywords and key phrases for the pay-per-click systems right out of the shoot. In some competitive categories, companies are paying up to $80 per click, so you need to keep in mind your budget for advertising.                             Did I get your attention yet?

HOWEVER................

IF you have some time to spend with your webmaster developing your website and investigating your target market on the internet (keeping in mind that you've hired the right SEO to do your website), then you may have a great chance of landing number one or three four five up to 12 positions on the first page of the search on any search engine for that particular keyword or product.  Those nicely placed listings are called "natural listings" because they are naturally selected by the search engine based on the fact that parts of the website match what they are looking for.  And they are always looking for relevancy.   Then during the time when the search engines are processing your submission requests, you might think about doing some payperclick to supplement your income until the search engines pick up your website and decide where you land in the searches.  Then lastly, if you have some keywords that rank well and a few that don't, just do pay per click on the keywords or products where you are weakly represented via the searches.

Don't spend your hard earned advertising dollars on high frequency keywords unless you have money to burn. Most companies want to pay for the highly targeted low frequency keywords, and make that thousands of them. Depending on your market, you could pay a minimal fee for highly targeted clicks into your website.