Even if you don't need sub-second updates polling is still very wasteful. Your typical HTTP header is 700-800 bytes, so every 100,000 requests you're sending 75 megabytes of data you don't need to.

Websockets require 2 bytes, so those same 100,000 requests send only 200 kilobytes of additional data. Also it's worth noting that with Websockets data is only sent when there is new data to send. Saving you even more bandwidth.

Plus with services like Pubnub & Pusher websockets are really simply to get started with now as well. I would argue they're actually easier to use than polling.