Michael Martinez of SEO Theory says you should stop writing meta descriptions. Why? Because the search engines ignore them. But do they?
Yes. Sometimes they do. But many times they don’t. Which is why you should continue to write your meta descriptions.
What the search engines don’t do is use your meta descriptions to rank your websites. However, they DO use them for their snippets. Not all of the time. But much of the time. And because they do use your meta descriptions some of the time as search result snippets you should go ahead and continue to write them.
So when do the search engines use your meta descriptions for search results snippets? Typically, when it suits them. Technically, when those meta descriptions are just right for the search query.
What it really boils down to is control. Do you want Google and Bing to control what searchers see in the search results or would you prefer to have some of that control for yourself? Remember, there’s no guarantee the search engines will use your meta descriptions at all. But when they do, you want them to use the meta description that you wrote. You’d prefer that, wouldn’t you?
If you want to leave the perception of your business and your web pages to Google’s and Bing’s ability to present your information, then by all means stop writing your meta descriptions. But if you want to have some control over your reputation, then go ahead and spend a little extra time crafting a good meta description.