I've been thinking about how the quality can be improved in addition to the merit system.

1) Allow forum moderators to penalize users by revoking signature display rights for a month for poor posting habits.

2) Penalize bounty campaigns and ICO's that use bumping by shit-posting by displaying their thread permanently on page 10 or a special penalty page which reduces the size of their images and fonts.

3) Provide preferential listing on page 1 for ICO's and Bounty campaigns that pay to be listed there. Rather than paying an army of shills they could be paying bitcointalk to be listed on the first (featured) page.