Why do I need to write meta descriptions?

[matt-14567]

I'm confused about exactly when Google displays your meta description, instead of a random snippet. I just did a search using a term that I knew would bring up a site I'm familiar with. I know for a fact that meta descriptions were written for every page on the site (not by me), but Google didn't display one when I did my search and the site turned up in the SERPs. Instead, it displayed a random snippet with the keywords that I had used in bold.

Why is this?

[inhouseninja]

It really depends on the page and the website.  But, as a rule, I think it's always smart to write a meta-description to gain the trust and attention of your potential visitors.   As you probably know, the meta-description usually shows up under the Title and URL in a Google result.  This bit of text could potentially set you apart from your competition.

It's true that Google will grab a bit of text and use that for a description of the page by default, but Google is a robot and probably isn't going to grab the most important text in the article. It will simply grab some text with the related keywords usually.  It certainly isn't going to put together a catchy sentence / summary for searchers to read.

To make this as clear as possible, let's take a search for "cheap headphones":

We have the #1 site that uses a meta-description -
"Cheap headphones and discount headphones, Get information on all types of headphones and find the secret to getting the best deals and what website sells them for the best price."

Then we have the #2 site that is letting Google choose its meta-description text.  It looks like this:
"20 results – Our top picks for the best cheap headphones around in 2010.

| $19.95 | sugg. retail price: $22.95 | Kidz Gear Headphones | Excellent ... |
| $19.99 | sugg. retail price: $19.99 | Koss KSC 75 |

Surprising high ..."

|

These aren't great examples because the #1 site has a description meta-tag that is too long.  But I think it gets the point across.  It's a lot nicer to read something that is concise and grabs the searcher's attention than to hope Google is going to pull the best information for the user.  Human wins vs. Google this time.  (for now).

[DougRoberts]

Did the meta-description have the keywords in?

[matt-14567]

No, it didn't. Is that the only way Google will display the meta description? If so, that makes sense and clears up my confusion.

[ksracer]

Traffic is pretty quantifiable, but conversion perhaps less so. What good are strong SERP's if users aren't clicking through to your site and converting. Well written meta descriptions are an important part of the funnel, and what is the cost of creating them? Time?

[DougRoberts]

If your meta-description doesn't contain the search keywords then google may view a section of your page that does as more relevant and return that instead.

[BTeubner]

Tell your boss that the website's flux capacitor will get overloaded without a good meta description.

[ksracer]

Yep, with good meta descriptions traffic will hit 88mph in no time.

[Wales]

If you have a key generic keyword phase that describes the product but not the brand and is strong ($10 PPC), should these phrases be first?

Also, should my brand names be in Meta tags?

Note that I prefer responses from individuals familiar with Yahoo RTML. due to what I think is automatic meta tags.

[TimKelsey]

Has there been any research done on CTR for written descriptions vs. snippets grabbed by Google? Personally, I hardly ever look at meta descriptions when searching for something. My judgement is mostly based on the title tag.

Logically, it makes sense that a well-crafted description would be better, but I'd like to see some hard evidence to back that up.

[DougRoberts]

Here's an article I found about search snippets affecting click throughs. (In this case it was the presence of an article date that was causing a drop in CTR.)

Evidence of “SERP Snippet” Impact on Clickthrough Rates

And this article about boosting traffic by changing your snippets:

Easy Way To Boost Your Search Engine Traffic

I agree, that it would be to do some more testing of the impact of optimising the snippet for conversion.

[TimKelsey]

Cool! Thanks Doug!