It has been awhile since they did a door to door campaign with a tract specifically designed to invite the public to the convention.
But the last Kingdom News tract campaign was in October 2000:
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km 10/00 p. 8 par. 2 "The New Millennium—What Does the Future Hold for You?" ***During the months of October and November, we will have a special opportunity to provide our neighbors with the answer to that question. How? Through the distribution of Kingdom News No. 36. It is entitled "The New Millennium—What Does the Future Hold for You?" During the first half of October, we will offer the Watchtower and Awake! magazines. Then from Monday, October 16, through Friday, November 17, we will engage in an intensive distribution of Kingdom News No. 36. During this campaign, we will concentrate on placing Kingdom News No. 36 on weekdays. On weekends, we will present it along with the current magazines.
I found this mention of a campaign on the Friday morning of the 1978 convention where handbills inviting the public were the main part of the process. This WT technique started in 1936.
1978
*** km 5/78 p. 6 1978 Conventioners in Action! ***
At the close of the Thursday afternoon session, complete announcements and a demonstration will be given as to how to perform the service on Friday morning. Also, at the close of this Thursday session there will be released small, opaque, plastic witnessing bags for $1.00 each. Each bag will contain a supply of magazines, handbills and the release made on Wednesday. These items will be offered to the public in our field service. The plastic witnessing bag will have marked on both sides: "1978 ‘Victorious Faith’ International Convention of Jehovah’s Witnesses." This bag can be carried so that the public can see these words. Whatever literature is left over may be used on the way home or in your home territory.
Each witnessing bag will have sufficient literature for one or two publishers who may work together. It may be that at each hotel or motel special desks may be permitted in the lobby from which the assigned captains may issue territory. If so, the territory for each car group could be handed out Wednesday and Thursday as family groups come into the motel. Then at 9 a.m. Friday each group may go right out into the field for about two hours to complete the small assignments. There will be no need for assembling together for text and prayer. A few additional witnessing packages could be on hand Friday morning for those who may not have obtained their service kit at the assembly hall. Publishers may wish to bring their personal Bible along in case persons in the field ask questions that require a Bible answer. The plastic bag will be of sufficient size to hold the Bible in addition to the other items. The few words that need to be said at the doors will be explained at the close of Thursday afternoon’s session. Where the people do not accept the offer for the suggested contribution, the publishers should use the handbills to invite them to the convention sessions and the public meeting.
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yb79 p. 17 1979 Yearbook of Jehovah’s Witnesses ***Prior to the series of conventions an insert in Our Kingdom Service built up enthusiasm for the special witnessing featured on the third morning of the convention. In most of the cities where this was carried on, an attractive yellow and blue plastic service kit was also included for use by the conventioners. Each service kit contained copies of the new brochure entitled "Jehovah’s Witnesses in the Twentieth Century," which was released at the convention on the preceding afternoon. The kit also included current copies of The Watchtower and Awake! and the special handbills that were used to invite the public to attend the convention sessions and the public lecture.
1976:
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km 3/76 p. 5 "Sacred Service" District Assemblies ***Starting the weekend prior to each assembly and on until the day before the program begins, there will be a concerted effort made in and around the assembly city to invite the public to attend the entire program. Millions of handbills are being printed for special house-to-house distribution. Publishers living in the assembly cities and nearby will be invited to share. If you plan to travel from out of town to an assembly, could you arrange to arrive a day or two early to share in this work? If so, request your rooming accommodations accordingly. And on arrival at the assembly city go to the address of the rooming department for territory and handbill supplies.
1975. 1974, 1973
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km 5/75 p. 3 par. 3 Attend the "Divine Sovereignty" Assemblies ***Arrange your schedule so you do not have to leave the convention prior to 3:50 p.m. on Sunday, when the convention closes. It has been arranged to end earlier this year for your convenience in traveling. Do not miss the public lecture "One World, One Government, Under God’s Sovereignty." How many people can you invite to the public talk? There will be extensive handbill distribution in each assembly city for a few days prior to the assembly, so if you can arrive there early, you may share in this witness work.
*** jv chap. 17 p. 266 Conventions Proof of Our Brotherhood ***
Beginning in 1936, the convention public talk was advertised by orderly parades of Witnesses who wore placards and distributed handbills. (Those placards were initially referred to as "sandwich signs" because they were worn one in front and one in back.)
