Bitcoins safe?

I know you can do surveys and other CPA schemes to earn Bitcoin, BUT, on most of those sites, you can't even withdraw your earnings until you reach a certain threshold. That is the catch. The owners of those sites want to offer you Bitcoin to complete certain tasks but they want to make it difficult for you to actually withdraw because they are in it to make money. Bitcoin is valuable and I think you'd have better luck selling a product or service in exchange for the crypto.