Advertisement cost

I received a e-mail request from Elisa Hayden this week about my blog and she intend to put up a advertisement on my website. The following are the e-mail. Do you think it is genuine and how much should I charge for it.

Dear Sir/Madam,

Recently we visited your website (http://ttong3.blogspot.com/2011/03/donations.html) and found it very interesting. Given the relevance of your website to our business, we would like to offer an advertisement opportunity to you. We would like to put a text link ad on your homepage/main page. Our advertisement format is generally 15 words long and it will contain one to three text links, which we provide.

About our business,we offer consumers safe and easy way to apply for short-term loans .Please let us know how much would you charge for this kind of ad. We look forward to your reply and the opportunity to work with you.

Thank you,
Elisa Hayden
Senior Marketing Associate
Kaushik,LLC