Missionary slideshows are more and more a thing of the past, but when they were common place, I'd heard someone say that missionary slideshows were more for the missionary than they were for the group watching the slideshow. In many cases, the group watching the slideshow had little connection with those pictured in the slides, the faces in the pictures could've been photoshopped out of a National Geographic for all they knew. To the missionary, however, they'd invested their life into those people creating a deep bond. So while the audience, I'm sure appreciated seeing the pictures and hearing about the ministry, it probably meant more to the missionary. I've realized in recent months that bulletins (both the Sunday bulletin and bulletin boards) have a lot of similarities with slideshows.
Among church office circles, the Sunday bulletin is often viewed as one of the most ineffective channels of communication though for some reason it's the default channel utilized in many churches. If people read the Sunday bulletin, it's rare that they remember to respond to the items that caught their interest when they read it during the worship service. At least, that's the perception in the offices I've worked in. Bulletin boards run a close second.
My epiphany in recent months is that the Sunday bulletin or bulletin board is of high interest to the ministry or person who submitted the information for that publication. The group who requested a bulletin announcement for their upcoming excursion, flips through the bulletin to see their announcement printed. The ministry that requested a bulletin board to highlight their summer ministry week, looks to see the bulletin board. So even though it may not be the most effective communication method, it's important to those groups because they want to see their interest promoted in print. That's as far as I've gotten in my breakdown; I'm still extrapolating further conclusions as to where this leads and the impact it has on our communication methods.
Late addition - I found this correlating post today