i-Say is available in United States.
Try out this version!

To refer friends, you must be a Rewarding Panel member for 30 days or longer in the panel. Otherwise, you won’t be able to see the referral link.

After these 30 days as an active member, you can then simply click on the arrow on the top right side of the website, access the “Refer Friends” page and send the referral link to the people you wish to invite. You can refer as many people as you like, but you will receive points only for the first five successful referrals per calendar month.

The friends you refer must live in the same country as you, have a valid email address, be 15 or older, and must not already be a member.

After a month, you will receive 30 points for each friend you refer, who successfully registers as an active Rewarding Panel panelist and who completes at least one survey.

You can receive points only for the first five referrals.

Only when the referred friend finishes the whole above process, that the points can be credited to your account.

The points will be allocated into your account on the 25th of the month. You may check your points balance to find out if you had successful referrals.