The stats values of the player are not "live". This means, that the stats are not fetched from Battlelog every time you open your leaderboard. The stats are stored in a local database. And this causes, that the stats values have to updated periodically. It is recommended to update the stats every hour.
There are three ways to update the leaderboard:
Yes! By limiting the number of requests it is even necessary. I recommend to mandate a cron job, to call the update function every hour
Simply stated, the cron job opens a URL for you. Automatically. So you have only to tell the cron job the URL of the updater (can be found in the adminpanel of ezStats) and how often it should be called (every hour is recommended).
Free cronjobs you can create here:
There is no direct access to the stats from Battlelog. Therefore ezStats get the stats by using the puplic API from the site http://bf3stats.com
bf3stats uses a own database and so you have no realtime access to the stats data using the API. But ezStats can tell bf3stats to add new player to his database, and sync its data with those from Battlelog.
During the installation of ezStats your leaderboard is automatically assigned an ID number and a password. So your Leaderboard is entitled to register a new player at bf3stats.com and to syncronize data with EA's servers.
The comparison of ezStats' data with the data of bf3stats is unlimited. The order to register a player or to sync with EA is limited to 10 requests per hour.
By default, ezStats updates 15 players per call of the update function. You can set the value higher. When the loading icon does not disappear after the specified time, the value was too high. The number of players that ezStats can update simultaneously depends on the characteristics of your webspace.
Players who are not yet in the database of bf3stats.com, will be automatically registered by ezStats. It may take some time until the data is available.
By default, ezStats synchronizes with EA servers if the players data is older 12 hours. This setting was chosen because your leaderboard is only entitled to ten requests per hour. If you only have a few players on the leaderboard, you can reduce the time. Do you have many players on the leaderboard, you need to set up time. If you've exhausted your limit, the player got the state "error".