Thanks for the ideas. I haven't ever done that kind of outreach for shout outs. But I am going to be soon. I wasn't sure how to approach it.
It depends on what kind of website you have, you need to be unique or creative or just know what you're doing by years of work, or just simple logic here's an example:
Today on BHW someone asked me for my sig space
X member: Hey man, you are really funny. How much for your sig?
Me: How much you offer?

X member: How about 50% commission on every sale your sig sends?
So what you can find out by those 3 messages:
1. Is just a question
2. I don't know how much signature spaces are worth, since he asked me he probably knows, hence i don't want to undervalue myself or overvalue and look like a noobie (Easy to decline if it's too low)
3. He asks if i'd agree on 50% on each commission, so what does he gains with this?
3.1: Free signature space
3.2: More customers
3.3 He doesn't losses any cash regardless if i make any sales or not for him as he didn't pay me anything, he gains new customers only thing is that he gets 50% less, which is fine since all those customers he obtained with 0 efforts after all, so it;s free cash.
3.4 But this in a way isn't a win win for me, why? Members might see the banner or text that he gives me to put and buy later on without clicking through me or i just might not make any sales so my space was wasted.
4. In the end since i checked his marketplace thread i quite liked his ebook and offered him 1 month of my signature for the ebook and honest review, and now i am waiting if he accepts or not. This is somewhere in middle since he doesn't losses anything and neither do i.