It doesn't look all that good to me.

From reviewopedia:
"Well, the first question I always ask is whether or not the site charges you to become a member? Inbox Pays is completely free to join, so that’s a good sign. However, there are a couple things worth mentioning about the site before anyone signs up.

First of all, you must have a PayPal account in order to get paid. This means that Inbox Pays deals in real currency instead of gift cards and prizes, which is something many people like. However, they require that you earn at least $50 in your account before you can request a payout.

This is nearly twice the earnings amount required by most other paid survey sites. The truth is that each survey you successful complete generally won’t pay more than five dollars at the most, and successfully completing surveys is not the easiest thing. This means that you may have to complete many surveys before you can receive a payout, and some people may get frustrated and quit without ever receiving the money they have earned.

In addition, their promise of getting paid for reading emails actually means getting paid to click the links of advertisers that they will send you. And once you allow them to give your email to advertisers, watch out. You will likely be drowning in emails.

And the price that is paid per click will often be very low, and paid to Inbox Pays, who will then pay you a percentage of it. This makes the $50 payout look even harder to achieve.

In general, Inbox Pays is free to sign up for, so it’s not a scam, but you should be aware of what you are getting into. Remember, if you’re really looking to make money taking surveys, then make sure to sign up for multiple companies in order to increase your chances of success."

Source: http://reviewopedia.com/workathome/inboxpays-com-reviews-is-inbox-pays-a-scam/