Small ROI?

Nanotech and Commerciability:

In 2005 global government spending on nanotechnologies totalled $4.8 billion, according to the Cientifica researchers.

They say government nanotechnology funding takes an average of two to three years before it even reaches the lab, and consequently the impact of nanotechnology will only start to be felt from 2007 onwards.

It also warns that much of the government spending is concentrated on research areas with little immediate commercial impact.