Ya, a great trick is to always add that extra 1-3 cents because most people bid in even increments of 25 cents to a dollar. So instead of $15 go for $15.01 or something and you'll probably manage to pull off some one cent victories down the line.
But ya had they bid $15.00 and you had bid $15.00 before then them their bid wouldn't have gone through. So there are some strategies even to sniping in terms of when to place your bid.
On small ticket items where I know a range of $1.00 or so where the item price will end I always use a longer delay. Like 30 seconds. I do that so to thwart other snipers. Knowing that if I get my bid in first they'll have to up my bid by 25 - 50 cents. And sometimes that makes it more than a person would be willing to bid. Like on CD's and DVD's I do that. Oh, and I always use that extra 1 cent. So then maybe I bid $15.52 and someone else put in a snipe of $15.75 their bid wont go through because it's not 25 cents more than mine. Ya, they could win with $15.77 but most people dont bid like that. So the next highest winning bid would likely be someone willing to pay $16.00 but that gives me a 50 cent range with only 30 seconds left to bid. And maybe the item wasn't even anywhere near $16 until my snipe at 30 seconds left. So this works real well for me.