Staffing industry growth, with the exception of healthcare staffing, strongly correlates with growth in GDP, according to research from Staffing Industry Analysts. Staffing industry revenue tends to grow faster as GDP improves.

MarketWatch reported the 2.4% growth was almost in-line with 2.5% growth expected by economists. However, growth in real GDP may slow further in the second half of the year, according to some estimates.

"The post-recession rebound is history," said Bart van Ark, chief economist at The Conference Board. "We don't foresee a double-dip, but we do expect growth to slow even more markedly, to a 1.6% annualized rate in the second half of the year."

First-quarter real GDP increased at 3.7% after the Commerce Department conducted an annual revision for its estimates this month. Prior to the revision, the estimate for first-quarter growth in real GDP was 2.7%.

Real GDP declined at a rate of 2.6% for full-year 2009, according to the revised estimates.