The number of documents indexed in RePEc has recently surpassed 1.5 million. About 900,000 are journal articles, 560,000 are working papers and the rest is distributed across books, book chapters and software components. The number of documents available online is approaching 1.4 million. All this is contributed by over 1,600 archives, ranging from the major commercial publishers to small research centers.
I do not think we expected that many documents related to economics to be listed when RePEc was started. And yet, the number of additions keeps increasing. One would have expected all the low-hanging fruit to have been picked since 1997, but no, they keep coming. Fortunately, RePEc is completely scalable, so we are ready for the next half million. Some RePEc services (those using the RePEc data), however, start struggling a little bit with the mass of data. We expect that some efforts will be dedicated to back-end work for these services.
And if your institution or publisher is still not participating in RePEc, here are instructions. If you are an individual from an institution that does not want to participate, you can upload your works at MPRA and they will be included in RePEc.
The RePEc Blog 