The growing number of customer success stories and benchmarks has helped convince more businesses that speech is a viable business solution that provides measurable ROI benefits; by 2008, the global voice business market will be worth $3.1bn, with increasing growth rates through 2007, at which point growth rates will begin to stabilize and fall off as the market matures. While the platform market as a whole will continue to grow, it will have the lowest CAGR for 2004-2008 of any value chain segment. Speech recognition and text-to-speech engines will account for the lion's share of revenues within the segment, although voice authentication will increase in prominence, through 2005 and onwards. The applications segment is expected to become the biggest portion of the voice business pie by 2008, representing 32% of total revenues. Voice business services will be one of the fastest growing value chain segments through 2008, with a CAGR of 35%.