Isn’t it a bit weird to receive a bonus?

No, it’s “just” a different (and better) approach. Employers spend a lot of money on their recruitment campaigns and spend thousands and thousand to jobsites, advertising, recruitment agencies or head hunt offices. As we also offer the employers an appealing Service for much less money than they are used to spend, they can significantly save on their expenses.
Therefore it is interesting for them too to hand-out a bonus. The bonus in this case goes to the person who actually deserves it, and that is you! This way everybody gains.