Premium tokens in stronghold kingdoms allow two queue features, one for buildings and one for research.
Being able to queue buildings is quite a handy feature. It allows you to queue 5 buildings in each village at one time. This also means you can build a lot of buildings when you are offline if you build times are still quite low. It provides the biggest advance near the start of the game say when your build times are around 2 hours. It means if you are offline for 12 hours you can have 5 buildings completed when you log back in. its handy because you don’t have to keep building manually, what I mean is you don’t have to wait for a building to finish then put another on. You can just queue 5 freeing up your time for other tasks.
The key to becoming very strong very quick is researching as fast as you can. At the very start of the game you research times are very low. It starts off at a few seconds and as you research something the time increases up to a point where it can take over a day for something to research up. Just like the ability to queue buildings this benefits you the most when you are offline because you can queue 6 different researches and come back online to most or all of them completed.