Archives are widely recognized as a valuable resource for astronomy, but statistics on their use indicates they are even more important than most astronomers realize. Obviously much of the science from survey projects such as SDSS relies on the archive. Perhaps more surprisingly, archival data are also a major contributor to the science from targeted, PI-driven missions such as HST, Chandra, Spitzer and the ground-based observatories. Archival research currently accounts for half of the ~1200 Hubble and Chandra science papers published each year, and the use of the archive continues to increase. The archival data products are, in the long term, as important as the PI science programs.
It is vital to recognize the large impact archives can have on the science generated by missions and observatories. The value of the archive should be an important factor in the establishment of new projects. Future missions and observatories should not only budget adequate resources to support a robust archive, but they also should consider the effects of mission design and operations decisions on the archive. Additional funding both for archive users and archive centers -- particularly with an eye to enabling cross-archive, multiwavelength science -- is a relatively inexpensive way to increase the science output from our major investments in large projects.