The shift away from abstracts prepared by volunteer subject experts to those prepared by full-time, on-site specialists has occurred for three basic reasons. First, the continuing expansion of the chemical literature made larger groups of volunteers necessary, and the administrative effort of identifying, training, coordinating, and editing abstracts from such a large and widely scattered group became increasingly difficult. ... Second, computer processing was making possible increasingly rapid and efficient work-flow patterns throughout the late 60s. ... Third, the financial situation had improved to the point that CAS was able to pay full-time chemists to abstract and index. Increases in the price of CA had brought the organization self-sufficiency and the freedom to put itself on an improved business footing.
Dale B. Baker et al. J. Chem. Inf. Comput. Sci. 1980, 20, 193-201
Given the emergence of worldwide all-volunteer documentation efforts like Wikipedia, perhaps now is a good time to reconsider the feasibility of a very different form of all-volunteer chemical abstracting service.
The all-volunteer system was used by CAS almost exclusively until 1966. Although these abstractors were called "volunteers", they did receive a payment for their work - about $0.18/line in 1979. This would have probably not been insignificant for some abstractors, adjusting for inflation, but on the other hand, this kind of work was most likely very laborious and time-consuming. The effective hourly rate was probably quite low.
Each of the three reasons given above for moving toward an all-professional service can be viewed from a very different perspective in 2006 than was possible in 1980. The rise of ubiquitous network computing and self-organizing user communities largely neutralizes the first issue of cost-effectively coordinating the efforts of an all-volunteer group. Regarding the second issue, the work-flow optimization that is now possible far surpasses that of 1980. The third issue may be the CAS system's greatest weakness. It is certainly the issue on which an all-volunteer service could gain the most ground over commercial offerings, not unlike the difference between commercial software and open source software.
Finally, what's most thought-provoking was what wasn't said. The move toward an all-pro system had nothing to do with the lack of qualified, enthusiastic volunteers, as the numbers in Figure 6 can attest to. Rather, the main issue was the difficulty of getting these volunteers to be productive in a cost-effective way. On this score, 2006 couldn't be more different than 1980.