What commission to pay 3rd party ad agent?

my site: 17k visits per day on science & tech

[johoney]

Hi - Up until now we've relied on adsense and some affiliate ads. Now we're considering paying an agency to sell our ad space.

What is a fair % commission?

Cheers - JoC

[eljefe3]

Whatever you both can agree upon that is fair. Link sales usually get up to 50% commission, so that would be a starting point although I'm sure you would feel that is on the high side.