This isn't a good idea for a business. This forum is being spammed enough without you guys spamming in other people's name.
You have to understand that campaigns are made to reward posters, allow them to earn money on the side for posts they would've made anyway. If someone is unable to post due to whatever reasons, like being tired, not having enough time, being sick, he shouldn't look for replacement! There are things in life you have to do by yourself or they won't count.