A friend of mine showed me a website called BitLake which pays investors 10% daily.

The minimum to deposit is 0.001 Bitcoin
The minimum to withdraw is 0.0005 Bitcoin

Are they paying people?

Yes. Each withdrawal is shown on their payout page. You can view each transaction by clicking a transaction link.

Is this a Ponzi scheme?

Bitlake does not disclose any information about how they are generating the Bitcoin. The main reason for this is simple, a 10% daily return (forever) is not possible. Yes this is a Ponzi scheme. However this one is only 5 days old and being early to a Ponzi scheme means that you can profit.

Ponzi scheme investment advice

Only invest a small amount of Bitcoin and withdraw your initial investment amount as soon as you make a little profit. Ponzi Schemes will end horribly, but they start out great. Take advantage of the early days of the program and withdraw frequently. Don't be greedy. This program will not last forever.

Join BitLake at your own risk