Your rings are Soulbound.
Ultimately, this means (with a few exceptions):
You cannot sell your rings.
You cannot trade your rings.
You cannot gift your rings.
When you receive a ring in the game, it is automatically Soulbound.
As I said, there are some exceptions to these rules; if you received your before the
8th of December 2008 then your rings are not Soulbound (as in, exempt from the above rules). This stands unless you equip the ring or rings in the game. Is in, placing them in the ring slots in your tool bar; if you do this, the ring you place in there will be Soulbound. This means the ring will follow the mentioned rules above.
There are three rings that will not be Soulbound, Sweet Heart, Fortune's Favour and Sugar Rush
ONLY. With no Soulbinding, come some rules, you
cannot Swap the CL of this ring with these rings, you are also unable to
Salvage these rings. You are able to Sell, Trade and Gift these rings.
Then, you ask, why do I see rings for sale in the Marketplace?
As mentioned above, if you received a ring before the
8th of December 2008, then you are able to Trade, Sell and Gift them. People have decided to make a few hairy gold by selling them on the Marketplace.
But why are they Soulbound?
I want to make lots of money too. But, if you look at this graph,
You can see the effect of unsoulbound rings. Before the Soulbinding, the rings were near worthless with hundreds of rings in the Marketplace. This made it way to easy for people to buy their way through the game, you could buy all 40 rings at CL 10.0 for a total of the price of one ring today. But, then you look at the graph after Soulbinding came in place, the price goes up dramatically, this makes it harder or near impossible for people to buy their way through the game. Kudos to the developers for this idea!
For a more
*cough* authoritative approach view
Qixter's sticky about Soulbinding in the zOMG! Forum Archives.