Greenzap isn't operational yet. Its big draw is that it will give you $25 U.S. just for signing up. If that doesn't sound like one of those "If it's too good to be true..." things, I don't know what does.
To make things worse, GreenZap is using a multi-level marketing approach, which isn't illegal on its own, but a large number of MLM companies fail within the first year. Greenzap states that if you get other people to sign on to Greenzap using your ID, they will get $25.00 and you will get $5.00 BUT if you become a GOLD member (by depositing $100.00 cash into your GreenZap account) you will get $20.00 for every person you brought into GreenZap who ALSO deposits $100.00 to become a Gold member. So while it doesn't "cost" anything to sign up with GreenZap, it rewards you if you're willing to deposit money with them for the purpose of making more money from them. Sounds like an appeal to the greedy.
Assuming the business is legit, which hasn't been established yet, if the company promotes the recruitment aspect of the business ahead of the money transfer service they are liable to be investigated by authorities and possibly shut down.
To make things even more worse, the ownership of the company have been tied to disreputable MLM companies in the past. There has been a website set up my an individual who has collected information that he believes shows GreenZap to be a scam in progress: greenzapscam dot com.
The biggest defence you will hear in favor of GreenZap's $25 giveaway is "PayPal gave away $5.00 just for signing up for years...". While that is true, it was $5.00, not $25.00. Giving away 5 times more money than PayPal shouldn't put necessarily put confidence into the marketing plan, it should make you wonder where all the money is coming from. Greenzap's fee to transfer cash is a flat rate of $1.00 per transaction. Not a lot of money considering they have to front everybody $25.00 to start off with.