Each service has a different limit. In reality it won’t matter on your end, if you ping to often for a service they just reject the update and go with the last valid ping.
Here is a service that pings many sites at once:
http://pingomatic.com/
So if I wanted to be on the safe side I should start with the story I’d want to get most pinged first, yes?
Each pinging services has their different limit. Also the pinging is done sequentially. So if you have a lot of services to ping then post submission time will increase.
The other thing you need to know about the automatic pinging services is that it doesn’t display any errors for failed pings. So it is like working in the dark and hope that the ping succeeded 🙂
If the services pinged by pingomatic are good enough for your needs then you might be better off to check the required pings in pingomatic and create a bookmark. After you are done with your batch update you can just click on your bookmark to ping all of them at once.
