Are Meta tags useful for SEO? [duplicate]

Question

Possible Duplicate:
Which meta tags are not worth the effort?

Reading a Search Results with this or a similar phrased question can lead to reading a lot of conflicting answers. Are there any meta tags that matter in SEO?

From what I have read I do know that meta keywords are no longer used (or so little it is not worth using them) and don't worry with using them.

Meta Description tags are not used for page ranking but can effect click through rates so should be used but be less than 160 characters.

I know the following meta tags exist:

• author - the author's name and possibly email address
• robots - to allow or disallow indexing by robots
• copyright - the copyright date of the page

How much do these meta tags matter and are there others that are new (including ones that may not be used by all but might be used in the future or are used by only one of the big players like Google or Bing) meta tags that should be included?

Note: Even if a meta tag doesn't matter in SEO but helps with click through rates similar to the descript tag does then feel free to include it with your answer.

Answer 1

Google may change the description snippet based on a search result. Some sites like stack exchange have decided to not use meta description tags to save on bandwidth and let Google build them. Title tags are pretty helpful I wouldn't ignore them and have Google try and build them. They'd probably just drop your rankings if they were blank. Google often uses w3c standards, and as you know microdata formats even the betas schemeas. I would use all meta tags that are appropriate for my site. The best way to see if meta tags affect your organic rankings is simply remove all the meta tags from your home page and see if it drops in rankings.