Pros & Cons

Pros

You can improve the search engine ranking of almost any webpage with just a couple hours of editing.
Internet users who reach your website as the result of a Google or Yahoo search are actively seeking the content you provide. These visitors will have the keenest and most immediate interest in your issue. As a result, their response rate to your call-to-action will be higher than visitors attracted by any other internet marketing technique.
By optimizing each of your webpages for a different topic, you create multiple entrances to your website that can directly attract kindred spirits.
Copywriting for search engines is relatively easy, mostly non-technical, and requires minimal training. Existing staff or volunteers can be trained to handle the re-writes, at no incremental cost to you

Search engine rankings below the top 10 don't matter much, because few internet users scroll that far. So, while you may "feel good" about improving the ranking of a webpage from 12,540 to 16, your website won't experience much improvement in traffic volume.
It's quite common for 50 million+ webpages to compete for a top 10 position at Google for any given search term. Thus, you only have a one in 5 million chance of being happy with your search-engine copywriting results. (Well, not really. The situation isn't as dire as the math would suggest, because this chapter will show you how to out-wit and out-write competing webpages with opposing points of view. But, the odds are that you will fail far more often than you'll succeed at achieving a top 10 ranking when optimizing a webpage for a competitive search term that generates a lot of traffic.)
Grossly over-stuffing keyphrases on a webpage could make that page annoying to read and could get your website penalized (or even banned) by search engines.
Unlike many other online advocacy techniques, copywriting for search engines does not yield immediate results. An improvement in a webpage's ranking may take weeks to occur.
Even if you follow every stitch of advice in this chapter, the best copywritten webpage can be outranked by a lesser-quality page that is promoted with an inbound link campaign.