(You should) take this one! You won't regret it
これを買って！絶対に後悔しないから！
「絶対に後悔させません」という表現ですが、
「あなたは後悔することはないよ！」という言い方にしてみました。
"You will never regret it"とすれば、より強い気持ちが表現できますね。
”regret”は「後悔する」です。
A 'sound investment' is spending money on something that will provide a benefit or return. Eg. "Putting money into renewable energy represents a sound investment in the current economic climate."
sound investment'（堅実な投資）は、利益や見返りをもたらすものにお金を投じることをいいます。
例えば：
"Putting money into renewable energy represents a sound investment in the current economic climate."
「再生可能エネルギーにお金を投じることは、現在の経済環境では堅実な投資と言えます」
"You won't regret buying this." means that if you buy a certain product you will not have any bad feeling or regrets for the purchase because the product is so good or useful.
The two sentences you see provided above are terrific ways to express to your listener that they will not regret buying a certain product. In the second sentence you will see the term be sorry about. This means to regret. This is a term that is appropriate for both formal and informal settings. It would make a great addition to your vocabulary.
If you're not completely satisfied with this product, you can return it for a full refund, no questions asked.
This product comes with a 30-day "no questions asked"return policy.
1. If you're not completely satisfied with this product, you can return it for a full refund, no questions asked.
This claim reassures a potential customer that this is a risk-free offer to try a product. By offering a full refund, this also adds validity to the idea that this is an unbelievable deal, and the product that will not only meet expectations but exceed them.
2. This product comes with a 30-day "No Questions Asked"return policy.
By offering 30 days for a customer to try a product, with the opportunity to return it if dissatisfied for any reason, this increases customer confidence in the product, as well as the company. The 30 days serve as a sort of trial period for a customer to determine if the product is worth keeping. This type of offer increases customer loyalty.
1. If you're not completely satisfied with this product, you can return it for a full refund, no questions asked.
（この商品に100％ご満足頂けなければ、質問なしで全額返金致します）
このように訴えると、その商品を買うことにリスクがないことが伝わり見込み客を安心させることができます。全額返金を申し出ると、それが期待を裏切らない素晴らしい商品・条件であるという主張に説得力が出ます。
2. This product comes with a 30-day "No Questions Asked"return policy.
（この商品には30日間の無条件返金保証が付いています）
ここでは、商品に満足してもらえなかったときの30日間の返金保証を付けています。これにより、お客さんの会社と商品に対する信頼が高まります。この30日間はお客さんがその商品を持ち続ける価値があるかどうかを判断するお試し期間です。このような申し出はカスタマー・ロイヤルティを高めます。
This product is 100% satisfaction guaranteed or your money back.
❶Please buy this product! You won’t regret it!
(この商品を買ってください。後悔しません！)
商品ーproduct
後悔ーregret
よく広告で使われるスローガンで、こういうのがあります:
❷This product is 100% satisfaction guaranteed or your money back. (この商品はあなたの満足度を100パーセント保証します、でなければ全額返します)。
参考までに！
You'll not regret buying this.
Buy this, you definitely won't regret it.
I'm positive that you will love this product.
I'm confident that this product is perfect for you.
Are all suitable examples of phrases which can be used in this situation.
You'll not regret buying this.（これを買って後悔することはありません）
Buy this, you definitely won't regret it.（これを買ってください、絶対後悔しませんから）
I'm positive that you will love this product.（間違いなくこの商品を気に入ると思います）
I'm confident that this product is perfect for you.（この商品はあなたにピッタリだと思います）
これらは全てこの状況で使うことができます。
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アメリカ合衆国 
