I basically wanted to add more than zero caching without adding invalidation code necessary for longer caching times  And in some cases when the thing your caching updates frequently enough, you don't really want to invalidate, you just want to set the longest time possible that from the user's perspective will not seem like cached/stale data.

In this case the user can probably have category counts that are 5 seconds stale, but this will still be a very useful cache if this code is getting hit several to hundreds of times per second.

I don't think this code will be hit that much, but setting a low TTL like this is a good start when there wasn't any caching before.