Well, yes you could have a cookie with C=C+1 and carefully set the expiration to the end of the day (like the article), or you could use randomly generated last

Well, yes you could have a cookie with C=C+1 and carefully set the expiration to the end of the day (like the article), or you could use randomly generated last-modified times and deduplicate server-side (similar to how cookies are usually used), but I can think of a few reasons the cache would give greater precision, so even if a lot of the same things are the same, I'm not so sure it's really "no different"; these things are pretty important to (some) publishers: - third-party cookie blocking/notification features in browsers - review processes on ad networks checking for actual cookies rather than suspicious last-modified times