CB Invites allows users to invite others to join the site. It keeps track of the invite and when it was accepted in its database table. That information could be used to generate coupon codes or something of the sort, but you'll need a Professional subscription as you'll need CB Invites and probably CB Auto Actions to generate coupons.

Thanks for the response. I do have Auto Actions, but there is no trigger for anything with CB Invites. I would like to setup a few things like the redirect after a user invites another. I also would like to setup the coupon creation like you mentioned.

Your CB Auto Actions release is likely out of date then. The triggers you'd need are as follows.

Invite Create: invites_onAfterCreateInviteInvite Accept: invites_onAfterAcceptInvite
I've included the actual trigger above so you can see the variables the trigger contains. The user variable in the accept trigger is the user object of the user accepting the invite. The user id of the user that sent the invite is in the first variable as [var1_user_id].

but back to the actual topic, what I am looking for is notify the person who has made the invite if the person they have invited has subscribed (paid) to a service. That is when that user who made the invite will get their $25.

Yes, that's possible. Using CB Auto Actions and its Query action to act on the invite accept trigger you'd insert a coupon into the database for that user to use. You'd then send them an email with a second action acting on the same criteria as the first except it's an Email action.

The below tutorial shows how to generate coupons using a database query. It does so using CBSubs SQL Actions, but it should be a good starting point.

www.joomlapolis.com/support/tutorials/107-use-cases/18407-purchasing-discount-coupons