Iran and Venezuela sell oil at a discount to certain favored friends. They use oil as a tool of foreign policy. To get a nation to go along with it in the UN and in a dispute with the United States. Iran is selling oil to the ChiComs under long term contacts signed at lower prices
What percent of world oil is NOT sold on the spot market? My contention is the developed world pays $73 but many 3rd world nations don't. Venezuela is using oil as a foreign policy weapon in Latin America. To make it's oil dependents toe the line
Recall the back-door deal Saddam made with Syria's Assad. During the period of 2000 through 2003 Saddam shipped his crude via the Iraqi-Syrian pipeline, under the UN's 'oil-for-food' (profits). Saddam's deal with Assad was Syria would pay 50% below the global spot price (in cash-Euros) and then Syria could label the crude oil as Syria's and sell it on the open market at the spot prices. The same deals are ongoing with America's worst enemies.
American ground forces quickly closed down the Syrian-Iraqi pipeline within the first couple of days into the ground war to topple Saddam. Syria's thugs were ticked off :)
In terms of that great question "What percent of world oil is NOT sold on the spot market?" The amount changes on a daily basis.
Another major problem for US, comment like this:
"We do not rule out the possibility of pricing our crude oil exports in euros. That would be interesting for our European partners.
(Vladimir Putin, Russian 'President')