The primary purpose of this letter is to make sure customers and prospects come by to see you at a trade show. If you have a hospitality suite or are hosting an event, this would also be appropriate to mention.
1234, Main Street
Boston, MA 02123
08 April, 2005
<Recipient Address Goes Here>
We'd like to invite you to come see us at <name of trade show> at <location> <dates of show>. We're eager to show you <products or services>. Of course we will have people on hand to answer any questions you might have.
You may find our <booth/display> <location>.
We look forward to seeing you.
encl: <List of enclosed items goes here>