The meta description tag was used by the search engines for a time to measure the relevancy, but so many people that filled him with keywords, so long ago that has less weight. Google and Yahoo for a long time so do not take into account (say), but sometimes seems so.
However, the meta description can be vital for positioning campaign in the search engines have their maximum effectiveness and has nothing to do with scale positions: he has to do with traffic. To be as effective as possible, follow these four tips:
The description must be relevant
The description should tell the visitor that comes and goes to find if the visit. If the description does not match the content, you have a frustrated visitor to remember not to visit your site next time. This also strongly affects the conversion.
Your description is like an announcement
Yes, as you read. A description is not vague or boring will generate many clicks, it works with your description to make it as inviting as possible. Unfortunately you can only try to see what is most effective.
Google does not always include the description, if the keywords are the visitor wrote in the description, Google will put a section of text content. Although you can not optimize for all words, it can include those that give you more traffic. This without forgetting the two previous points, so do not waste time trying to get meaningless thousand keywords in the description.
Each page should have their own description
This is very obvious, but most of website leave this point. They make a description for the site and copied to all pages. Each page on a site has its theme and its description must be relevant to the content. We also avoid penalties for duplicate content on your own site.
Not only just being at the top of the results: we must win the attention of visitors. If you do not, all your optimization campaign will never reach their full potential. Learning from traffic, optimization and SEO can be a bit complicated, but worth it.