Remember that Patience is a Virtue
People will instinctively change and change their site until they get to the top. It is amazing to see the internet direct marketing medium. Change is normally a good thing, but you will want to wait a few months after your initial optimization before you start changing stuff.
After you feel the page copy is structured well for usability and SEO, then you do not need to change it repeatedly unless you are doing so for testing purposes. Many times, a better way to evaluate conversion rates is through a split A / B test using pay per click search engines, which is explained in the Pay Per Click chapter.
Search engines need to have time to react to changes. It is harder to list for a competitive term such as “search engine marketing” if your links also have a mix of “online promotions”, “search engine submission” and “website promoter”.
You must pick and choose, having few variations to make your linking appear natural. You do need to focus your anchor text around related niches. When you have mastered a couple of terms, you may try to diversify. However, you should choose new terms wisely and stick with them for a few months.
Search engines’ changing algorithms vary many times a month. Rank changes are normally due to algorithmic changes, and not relevancy or small alterations to page copy.
Frequent Changing Can Hurt You
If you are writing a blog of have content that is rapidly rotating, you page copy will be changing continually. That does not hurt you. The problem occurs when you waste your time obsessing and compulsively tweaking the same copy repeatedly. The time you spend doing this is better used for other promotions.
Changing your page copy and randomly mixing anchor text excessively will prevent your from gaining an online presence with good links. You will never know the best page format or layout for your needs.
You will have no way of knowing how you would rank if you wisely picked and kept your copy. Also, only change one thing at a time, because you cannot predict how changes occur when everything changes. When you site is a complete disaster, you will need a makeover. Otherwise, you should leave it alone and work on building relevant inbound links.