Hints:
1. Look at email address from sender.
If email is from AffManager@CASINO chances for direct ad sales/paid placement are possible.
if email is from AffManager@AffiliateCompany chances for straight paid placement/link deal are close to none…hybrid deals are possible. paid in advanced deals possible (against future commission)
if email is from whoever@3rdPartySEOCompany representing CASINO, chances for straight paid placement deal are pretty good (although I guess the contents of that email might be a little different).
2. To weed out the deals that wont do direct, be brief and to the point. It is your website, tell them your policy. No need to sell them on the idea, remember they contacted you and they want something from you. Tell them how they can get it.
“Thank you for your offer…I don’t do affiliate deals.”
“Thank you for your offer. The top spot on my site(s) require a placement fee”.
“Thanks for the email. Are you looking to advertise on my site or are you looking for affiliates?”