There are several sites who can do this for you, ranging from inexpensive to expensive.
I'm one of the expensive ones and I've been writing ad copy, promotional text, tour text for seven years, along with articles and press releases, copy for affiliate programs...damn...I don't think there's anything I haven't written yet.
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Webmasterlabor.com also does copy and they are very inexpensive. Gene is a real good guy.
Wetwords.com - Coy
Sex-story-text.com - Cheeky Marie
Very good people.