This AP article [1] (tech.yahoo.com seems to be having problems just now) says that the overall market fell by either 7.1% or 6.5% worldwide, depending on if you ask IDC or Gartner. US shipments were either down 3.1% (IDC) or <1% (Gartner). Also, the article mentions that Apple's market share increased, but doesn't have an estimate of its shipments.
So without knowing how NPD Group is counting, this 1.8% number is not very useful. If it's global, it makes Apple look pretty good. If it's US shipments, it's harder to say.
So without knowing how NPD Group is counting, this 1.8% number is not very useful. If it's global, it makes Apple look pretty good. If it's US shipments, it's harder to say.
[1]: http://74.125.45.132/search?q=cache:tw4QpCy8JFoJ:tech.yahoo....