Using a hits system on the web service files is the fairest and easiest way to control bandwidth usage for everyone who uses the Gold and Silver price API. If you wish to download the XML or JSON files every minute, you will use more hits than someone who only downloads a file every 10 minutes so you will need to pay more.
Hits also encourage more ethical and resource efficient programming. Many developers set a "cron job" or "scheduled task" to download the price files at regular intervals for display on a web page. This is unneccesary and only efficient if there is constant traffic on the page. Hits encourage the programmer to cache the price page and use a script in the header to only hit the price feed when an update is required.
Guide to hit consumption (the API does not consume hits while the market is closed)
- Update every 15 minutes = approximately 2,300 hits per month
- Update every 10 minutes = approximately 3,500 hits per month
- Update every 5 minutes = approximately 6,900 hits per month
- Update every 1 minutes = approximately 35,000 hits per month
HINT: If you do not hit the feed while nobody is looking at the result (most of the time) your hits will last much longer and you can update more often while someone is looking.