一封吸引人的开发应该具备那些内容我的写的开发

Qinyezhi：一封吸引人的开发应该具备那些内容？
我的写的开发信简单，发了很多也没见客户回复。之后我就反思了问题出在了哪？我的开发信框架大致如下，请大神指教，不胜感激。
Dear xxx
Hope you are fine.
This is Mark from HTD lighting.......................
Why choose?
1,..........
2,.........
3,.........
Here is our led strip and led module light for your reference.
Products specification:...................................................
+ picture 1, 2,3.
Waiting for your reply.
Best Regards,
Contact ID as below
Whatsapp:+8613537608408
Sky:htd169
Company profile
................................................