Building Referral Program Inside Application?

I have a point of sale application and am looking to grow my business. I have a reseller program that pay 20% that I advertise on my web site and e-mail signature.

I am thinking about putting inside the customer's dashboard. Once they close it, it won't come back (in case they found it annoying). Do you think this is a good idea? What text/copy should I use for it? Where should I position it (See dashboard below)

Here is what dashboard looks like now (First page after login). (A lot of these messages can be closed once done with learning about the system)