operational: icmp echo out of control?

Hello, I've observed that our border routers are getting pinged a fair bit. I measured on one router and saw: 5 per second, seems consistent throughout the day, roughly 40 different sources every 15 seconds I took a look at the varied sources and discovered that the sites are well connected and those that resolve resolve to akamai names. This isn't more than a nuisance for me, but I run a small net. Should I conclude that an ISP with a population 10 times bigger would have their border routers getting pinged at 10 times the rate I see? If so, should we care, or just ignore it? Thanks, -mark