Re:Good for them (Score 1)

Checkouts are only one of many metrics used to decide on purges (or weeding, to use the library jargon). Other metrics include physical shape, timeliness, format considerations, shelf space, historical value, rarity, cost to replace or update, reviews, outdated content, and much more.

Public libraries in particular rely heavily on checkouts as weeding metrics because part of their mission is to responsibly use city and state funds to support their communities. If the materials are not being used, it is an indicator that the collection is not meeting the needs of the community, and thereby that the library may be failing its mission.

As for your habit of using materials in the library and re-shelving them instead of checking them out, many libraries keep "in-house use" statistics that factor into weeding decisions. However, it's only possible to track in-house use of materials if patrons place used materials on the wheeled carts available, rather than re-shelving the items themselves (with [much appreciated] best intentions).

Lastly, the periodicals (termed Reference in Libraryland) aren't available to checkout because they must be available for the community to refer to. (Periodicals refer to materials that are periodically issued, such as journals, magazines, and journals.) It's likely that multiple patrons will need materials such as encyclopedias and government documents at one time; their usage will correspond with timely events such as assignments and tax season, so it's important that they're available to everyone.