Changing content on your website often is one of the most important things you can do in order to maintain a high search rank. Why? Simply put: Search engines are constantly on the lookout for new content to provide to their customers.

The appropriate rate of change depends on your goals. In a moment, I will offer a guideline for change frequency. But first, let me explain why frequency is so important...

Imagine that your website is like a bulletin board at the local coffee shop. As people come in and out of the coffee shop, they browse a look at the bulletin board and scan for something new. If this is their first visit to the coffee shop, they may consider everything to be new, and will be pretty excited about all the information.

On their next visit, the coffee shop customer will be eager to browse the board again. This time, they will recognize a few items, take note of some they missed last time, and notice anything newly posted.

On their third visit, they might notice that nothing has changed. If this is the case, you can bet that on thier fourth visit they will hardly take notice of the bulletin board at all. On subsequent visits, they will learn to ignore it all together. 'Nothing new to see over there' they might say.

Your web site is very much like the bulletin board. Search engines look at your site for the first time and get excited about new content. They quickly come back in a week or so to look for new material. If new material exists, they will come more and more frequently so as not to miss anything.

If your site appears stagnant, search engines will visit less and less frequently, reducing visits to as long as six months or more. This is a troublesome spot to be in because you might one day post something to your site that doesn't get indexed for several months. Bummer; your valuable new announcement will be hidden from the search engines for most of its effective time.

The answer: change (add) content often. Here are some guidelines based on three marketing goals...

1. Subscription or traffic-driven marketing goals. You want to attract users to your site in order to get them to subscribe and return often. You should be posting new content every day. This is a tough thing to do, and only works well in areas where you have a lot to write about. News sites, political blogs, how-to sites, and advice columns are perfect for this high level of frequency.

2. Product sales marketing goals. You have a product that you want to sell, and need to assure that the search engines are keeping you in a good position. Post 2-3 times a week. Make sure your content is relevant, and that you do not stray from your keywords. New content 2-3 times a week will give the search engines something to chew on, and assures that when they do come by, there is something fresh to bring them back soon.

3. Steady organic growth to build credibility. You have a corporate site, or a small business, and want to maintain good search engine credibility without becoming a professional blogger. Post once per week, and never less than twice a month. This will let the search engines know that, while you are not a power house, you have enough going on to maintain interest. Next time you issue an important press release, you will get into the search indexes in a week or two, instead of months.

In every case, make sure your posts are about 300 words, and chock full of relevant keywords. More than 300 words will start to seem like work, and fewer than 300 words will not be enough to convince the search engines that you are really saying something worth while.