I am always perplexed when an advertiser turns me down as a publisher. I totally understand why a brand may not want a bad neighborhood site, but this is certainly not the case with me. It seems like they are turning down free advertising! And, they don't have to pay out unless a sale is made! So, why turn anything down?
In some cases they feel certain publishers drive bad buyers. Those customers may complain more, ask for refunds... etc. I am not saying your site is like that, but that is the main reason advertisers turn down publishers.
I've been in affiliate marketing for around 15years mainly in adult, which I find it interesting in alot of cases now that I'm moving into more mainstream stuff, how many affiliate offers in mainstream limit themselves with rules that only seem to hurt their bottom line.