Rewards for contest and speedy projects will increase as time passes if the project hasn't been fulfilled. The objective of this behavior is to incentivize more Pros to participate and to allow more Pros, with higher rates, to be invited.
As Pros improve their stats, the reward offered to them will increase as well. We positively reward a Pro's experience and good performance! The more our clients choose a Pro as the winner of contests, the more reliable they become. This will result in more invitations to projects and higher rewards.
While simple projects may be accepted by Pros quickly, complex projects, or projects with very specific requests, may be harder to complete.
For more information on this topic head over to the community thread.