As far as returns for delegation, there are no additional requirements. To accurately calculate ROI you have to calculate the value of the BRO you are receiving vs. the value of the HIVE you are delegating. One BRO is worth significantly more than one HIVE at the moment. Holding BRO also earns you HIVE.
You can also delegate to @stickupcurator to earn their new token, Legion (LGN). Keep in mind though that the reward schedule is different (weekly I think) and Legion must be staked to earn hive, unlike BRO.
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