How do you encourage a referral for supportership? (in General)

I finally got a referral [usrname: caroline] who played more than 300 battles and even completed the tutorial. I've loaned her a few nice weapons at transfer fee basis but she doesn't seem to be logging on too much. So, how do I encourage her to play on and become a supporter, and a cool 900k into my account?

keep referring, eventually one of them will stick.

kewl, thanks, I suppose that's the only way to go about these things. Lucky I didn't transfer those items permanently, would've cost me a packet, lol.