In order to avoid omissions and faults, I recommends that fans have to take seriously with 20 key points below after finishing every development letter, because this is the final chance to check their appropriateness.
Title: Do you aim at the customer with a direct tone? Have you showed the advantage of your product directly? Is this advantage strong and concrete?
Product Benefit: Do you introduce the most outstanding advantage and profit first, and then account successively all your product profits to potential customers?
Competitiveness: Have you explained the dominance or uniqueness of your product or service in comparison with your rivals?
叙述语气：你是不是直接针对开发信的客户(即，直接使用第二人称的YOU)？例如，你应该说：“If you love horses you'll love this product”，而不是说：“People that like horses will love this product.”
Narrative Tone: Do you directly aim at the consumer? (which means using a second person pronoun “YOU”) For instance, you should say:”If you love horses you'll love this product”, instead of:”People that like horses will love this product”.
立场：你是否使用“You”（你，你们）远多于使用"I or We"(我，我们）？ 建议：在你的开发信里，前者应该是后者的两倍以上。
Position: Do you use “YOU” far more than “I or We”? Suggestion: In your e-mails, the former should be more than tripled comparing with the latter.
Style: Are your terms and paragraphs are short and sweet, so well as easy to read?
Vocabulary: Have you applied words with initiative and strong emotion? Do you always keep your writing goal is attracting the interest of the customer all along?
"Digging" Technique: Do you prompt the problems or troubles that customers are faced with, and then vividly describe all kinds of their burden and distress due to these problems or troubles, finally provide your product or service to settle their problems or troubles?
Coherence: Does your letter clear enough and easy to read? Is the transition of the segments natural and smooth?
Highlight Font: If the word or statement you emphasize highlighted or bold font? Only in this way can you attract the attention of readers, so that they can grasp your points.
Writing Intonation: Do you write in a friendly, proactive, equality conversational tone?
Factual Data: Do you use any solid data and facts to build your credibility?
Proof of Credit: Does your development letter include the materials to establish and proof your credibility? For example: Why are you an authority or an expert in what you say? Do you have any customer testimony? Do you have any successful case in the past?
No Risk Guarantee: Do you provide customers with no risk guarantee (such as: three guarantees)? If you pledge refund and the return, it will demonstrate your confidence in your product or service without doubt.
Marketing Reasons: Have you provided any credible reason for the project you promote in the letter? Do you give them actual price reduction benefits, let them receive immediate profits, so as to be your new customers? Or, the reason you give them special preferential price is that you have to reduce cost or clear storage space because of too much inventory?
订购步骤：你的开发信里有没有详细说明对方应该如何进行下一步？例如：Call (or fax) now for a trial order. （请立即来电或传真试单）；Or, simply fill out the form below,. enclose your check or money order for $28 0f sample charge, and mail to… (或者，填写所附表格，加上样品费28美元的支票或汇票，邮寄到……）。
Order Procedure: Does your letter contain a detailed account of what they should do next? Such as: Call (or fax) now for a trial order. Or, simply fill out the form below,. enclose your check or money order for $28 0f sample charge, and mail to…etc.
Order disorder: Have you tried your best to minimize your potential customers' order obstacles? Do you have a convenient and efficient way for your customers to order?
Order Award: Do you provide incentives, such as ordering awards, additional presents and so on? Or, have your product and service impressed the customers with an unusual added value?
Order Deadline: Have you created an atmosphere in which customers need to order at once in your letter, such as: invalidation of price, quantity limit, etc?
Comprehensive Answer: Do you have a complete answer to the customer's doubts, problems and concerns about the product and service .
Certainly, you can pay for consulting fees, then let the letter experts audit strictly, so that twice the result can be accomplished with half the effort. On balance, We should try every efforts to create a doubling of the business volume via the foreign trade development letter, and to play its proper value!