I really love the idea of marrying other characters in the game, and getting a boost to XP (albeit a small one) when wearing the ring. However, with all the set pieces and jewelry out there, getting married is practically pointless. It's not even an aesthetic thing since you, or anyone else, cannot tell you are married etc...
Here are a couple of ideas that MIGHT encourage more marriages in Tamriel (especially since this is Valentine's Day)...
1) Enable "House-sharing" for married couples that choose to purchase a home together.
2) Larger XP boost would be nice - and maybe double down on that if you do a dungeon with ANOTHER couple that are married.
3) Wearing the ring means breaking up a jewelry set - why not give the player a one time chance to select a set piece the ring will belong to (and watch those Pledges FLY off the Crown Store shelves if you did this and it was a legendary ring!!).
4) Allow the user to enable a "filter" that displays their spouses name under their nameplate in the world.
5) A married skill line? One whereby "guard" can be applied as a passive, or toggled etc...
Just a few ideas to make getting married in the game a little more appealing than just grinding up in Skyreach (which is practically it's only use currently).