pay attention. this is a risk and I would say even an hard risk. 8% is impressive amount as ROI in btc.
Just to mention other rates... there is a faucet that is offering around 3.5 % yearly - yeld is payed with mining profit.
a famous provider of financial service between 3-5% (it depends how many tokens you have) - yeld is payed with loans.
a gambling site = 15% yearly - yeld is payed "like a bonus" in a casino.
How they are providing 8% what is their business? how you decide to trust this service and not others?