Libraries are becoming increasingly interested in the services they are providing for their users. This is an important focus ― especially as more and more information becomes available electronically. However, the traditional strengths of libraries have always been their collections. This is true still today ― especially in research libraries. Also, collection makeup is the hardest thing to change quickly. For example, if a library has a long tradition of heavily collecting materials published in Mexico, then even if that library stops purchasing all Mexican imprints, its Mexican collection will still be large and impressive for several years to come unless they start withdrawing books. Likewise, if a library has not collected much in a subject, and then decides to start collecting heavily in that area it will take several years for the collection to be large enough and rich enough to be considered an important research tool.