Last week the US Mint ran out ofÂ silver coinsÂ and suspended sales, citing record-breaking sales of physical silver in the first month of 2013.
The United States Mint has temporarily sold out of 2013 American Eagle Silver Bullion coins. As a result, sales are suspended until we can build up an inventory of these coins. Sales will resume on or about the week of January 28, 2013, via the allocation process. — Treasury Department statement, Jan 17th, 2013. (Source)
The video below explains why the physical silver market is exploding: