Why does our homepage display the list of most popular guides this year? Why not keep a running total?
If we kept a running total of guide hits for your popular guides, it's likely that your older guides would be more popular simply because they've had a longer period of time to accrue those hits.
By resetting the statistics for popular guides, your newer guides and older guides are on a more equal footing. With a running total, a guide that was popular 1 or 2 years ago might still show up as popular, even if it hasn't been viewed in months.
Resetting the popular guides each year means it's more likely that the list will display what's truly popular now.