It is likely that keywords contained by URL, both in the domain name or in the file name, do have a minor but apparently positive effect on ranking and plays a very important part into search engines optimisation.

It also likely has an effect on CTR (Click Through Ratio) because keywords in the URL may make a user more likely to click a link due to an increase in perceived relevance.

The URL, like the Page Title, is also often selected as the anchor text for a link.
This may have the same beneficial effect as mentioned in SEO Page Title

If your website is hosted on Linux, you can make use of the .htaccess file to create Rewrite Rule and redirect long query strings pages to nice looking, friendly URL’s.

Example:

Current URL could be

www.domain-name.ie/pagename.php?a=1&b=2&c=3

From a search engine point of view, this type of URL format tells nothing about the page itself, but this example should:

New URL:

www.domain-name.com/details-Product-Name-Here-a1-b2-c3.html

To achieve this type of url’s, create a new file and name it .htaccess and ad the following line at the very top of the page:

Options +FollowSymlinks

RewriteEngine on

RewriteBase /#new rule

RewriteRule ^details-(.*)-a([0-9]+)-b([0-9]+)-c([0-9]+)\.html?$ /pagename.php?a=$1&b=$2&c=$3 [L,NC]

#where L = last rule, NC = case insensitive, (.*) = anything, ([0-9]+) = numbers only

Now change the link format on your page as shown in the example above and you are done.