I got some questions:

"Play MULTIPLY BTC or buy lottery tickets to increase your FREE BTC rewards by up to +0.00000969 BTC"
How does this work? How much should I play? Are there other factors?

"11. 9244% achieved towards the next +0.00000051 BTC bonus!"
What does this mean? What should I do to increase the %? I see it going lower and higher, but I don't understand what I should do?