Need help regarding data feeds.

I've received email today and it says,

=============
Hello my name is [her name] at [her company name] Inc

We are getting into mirroring our listings to other websites. This is how we came across your website.

We currently data feed to other companies that is done automatically through our website developer. Do you accept feed from third party companies?.

I would really appreciated your response to this inquiry so I can forward it to my Web Developer to get our listing on your website.
[her website]
=============

So what should I do now?
Any one have idea. I'm having classified web site. Can I earn with their data feed? will my rankings get dropped due to mirroring data?
I really appreciated your help regarding this.
Thank you.

Any one can help.?
Any idea really appreciated.