Hi Prutkar,
This 'HOT' tag obviously works slightly different than you expect it to. But it actually works as its supposed to.

Basically this is based on how "hot" an extension is considered from submission date till now.
This is not a day-to-day change in popularity.
The calculation of an extension tagged as 'HOT' is simply done by: 'All time visits'/'Days listed' > 'Set average'.
New listings are likely to be considered 'HOT' when lots of users visit in the first week they are listed (when they are profiled by being listed at the 'New Extensions' list'). The popular ones will keep the 'HOT' tag in the long term simply by being popular/high rated/well reviewed, and therefore most likely also well visited.
New suggestions for improved and perhaps even better or different tags and 'Top lists' are always welcomed and evaluated.
Sometimes suggestions are included for better funtionality, sometimes not.