I've been curious about how to optimize my lure usage to get the most bang for my buck - or to ensure I'm not squandering the limited time you get with them, as I don't have availability to play all the time. From these questions it's clear that using two lures on two pokestops in range will increase the overall spawn rate. My question is this - is it more efficient to use two lures at once, or keep placing lures consecutively on a single stop?
That is, which technique will yield more pokemon appearances per lure spent, if any difference at all? If I see a lure active on a group of pokestops, should I place another lure next to it or save it for when the first lure runs out?