hey anyone tell me how the RSS FEED readers like Google, Yahoo get to know and display the new posts in a RSS feed? Wat kind of approach they might be using on their side ? is tat something like pinging the RSS feed urls at regular intervals to get the latest post?
They generally scan your subscribed feeds at a scheduled interval. Like most feed aggregators they wait a set number of minutes between each check. I don't know the interval for the online services, but it may be safe to assume that they go out and check each time you log in.