1to gain an advantage or profit; to come out ahead (financially, practically, or emotionally).
昨日のセールで買えて、すごく得した気分だ。
I bought it at yesterday's sale and feel like I really came out ahead.
通勤定期を買えば月々交通費が安くなって得するよ。
If you buy a commuter pass you'll save on monthly transport costs and benefit from it.
ポイント制度をうまく使えば長い目で見て得することが多い。
If you use a points program well, you often come out ahead in the long run.