1987 Cleveland Indians Photocard
Team-Issued Stadium Give-Away Sets in Japan
1994 Chicago Cubs Old Style team issue photo card
1992 or 1993 New York Yankees postcard set (update)
They can range anywhere from fully featured baseball cards to over-sized photos to postcards to simple black & white cards with blank backs. They have been around for nearly as long as the hobby, but they definitely don't get the love or attention they deserve. These days, the most common way to acquire them would be as part of a "fan pack" from a team.
Nearly every winter, lots of collectors bombard teams with requests for freebies that can range from little more than a pocket schedule, to a whole package filled with cards, programs, t-shirts, schedules, posters or even a baggie of infield dirt from Fenway Park. With the evolution of social media in the last 4-5 years, lots of those collectors now post videos of their fan pack plunder on YouTube for the world to see (just search for "fan pack"). It was through those very YouTube videos that I was able to start assembling checklists for some of the team-issued photo card sets about which few collectors are likely aware. Along the way, once I've managed to identify years of issue, I've been adding these team-issued sets to the SportsCardForum Inventory Manager. Here are a few of the more comprehensive videos:
Now one team that does issue these cards, yet does not mail out fan packs, is the San Francisco Giants. I picked up the following Giants cards in a couple of lots on eBay, but I can't really pin down how they were distributed. I suspect they were distributed at fan events like the annual Giants Fan Fest or any other officially sanctioned autograph signing events. I've also seen them called "program cards," implying they may come with the game programs at the stadium, but I have no evidence to support that. These cards are slightly larger than standard, measuring 4" tall by 2.5" wide.
Since Carney Lansford rated a card in one of these sets, I'm holding out hope for the existence of a Hensley Meulens. I have no real personal interest in these beyond the academic, so all are up for trade or sale. These cards clearly represent a span of several years, so if anyone has information on these cards, like which designs are from which years or how they were distributed, please leave a note in the comments.
---------------UPDATE (15 Sept 2012)-----------------
With a little creative digging, I happened across a post on TheBenchTrading by someone who was able to attend the Giants Fanfest back in February. He posted several photos from the autograph sessions. Next to several of the signers are stacks of these black and white cards. Here is the link to the post:
SF Giants fanfest
Pay particular attention to the photos for Brandon Belt, Jeremy Affeldt, Santiago Casilla, Dave Righetti and Chris Stewart. There are also scans of a Brett Pill card and a generic San Francisco Giants card. I'm assuming those would represent the 2012 design. Since there is a Dave Righetti, I am even more hopeful of the existence of a Hensley Meulens card.
Based on my deduction about the next card following this one, I'm placing this design as from 2007, as it was the only year Dave Roberts played with the Giants, but NOT at the same time as Keiichi Yabu:
Since Keiichi Yabu was only with the Giants in 2008, I'm placing this design as 2008:
Based on various Giants Fan Fest posts, I'm assuming this design is from 2009:
Based on rosters, I think the similar series, without the uniform numbers on front, are from 2010: