Motive for query string parameter named url

why is someone appending this param to my pages?

[Lilliabeth]

When reviewing our web logs, we often see attempts to hit urls on our web site where the caller has appended a querystring with a parameter named url. For example:

http://www.example.com/somepage.aspx?url="http://www.somesiteweneverheardof.com"

Is there any legitimate purpose for this or is it nefarious?

[cgrantski]

Maybe they want you to visit their site. A really dumb way to build site traffic stats, either to impress their advertisers or to get you to buy something. Or to hijack your browser.