Recurring Collection-Related Challenges

Continuous expanding or rotating your NFT collection can easily result in an increased ROI.
As holders add more NFTs into their personal collections, they will be incentivized through various challenges requiring them to complete certain subsets of NFTs, for example: a full set of all Gold Tier NFTs, a set comprising all physicists or biologists, a set comprising all tiers of NFTs belonging to one specific scientist, etc.
Note: The examples above are purely illustrative and do not necessarily reflect the actual subsets which will make up the Achievement Challenges.
Collecting such subsets of NFTs will encourage users to stay active and frequently customize or expand their collections, thus consequently increasing the prize pools of the rewards - since a portion of each prize pool is derived directly from the secondary market royalty fees (as well as mint proceeds).
Additionally, certain NFTs will periodically benefit from an increase in demand, in relation to the Collection-Related Challenges - making the "buy and hold" strategy viable for early investors and/or holders of a great number of NFTs.