You can easily reward people for their Ideas and contributions from within a Challenge. Under the persons name, click the '...' button, this will open a context menu, from here select 'Reward this Idea'. You can also give a person a Reward directly from their Profile page.
From here you will be able to choose a reward to give to this person. Once you have chosen a suitable reward, press the 'Give reward now' button. The recipient of the Reward will be notified by email and it will be visible on their Profile page. You can now organise giving the actual reward to the person.
There are some Rewards that are pre-loaded into innoloop, but you can easily Add or edit your own Rewards.