An Post Greeting Cards. 
Since An Post is a private corporation, albeit owned by the government, it has the freedom to compete with other private firms in areas not traditionally entered by the government-run post office. One of these is illustrated post card sales. Since what An Post sells is a postal card, including the stamp, it places itself in a unique niche unavailable to commercial vendors. Since they are postal cards, they are listed in philatelic catalogues, thus collectable.
One interesting area is that of St Patrick’s Day cards. It is appropriate to send greeting to friends and relatives wishing them an enjoyable holiday. (Figure 1)
Another, and related theme is that of Peace.(Figure 2)
Ireland has many scenic areas. Since the Post Office is already selling postal cards, why not add a photo to the backside? The added convenience for the tourist of not having to purchase stamps is worth the difference. Also remember that, once written, they can be put in any of the ubiquitous green postboxes.(Figure 3)
Subjects seen on stamps are certainly fair game! (Figure 4)
Why not stamps themselves? (Figure 5)
And while we are at it, it is certainly not unfair to promote collecting and STAMPA. (Figure 6)
Let’s promote Ireland’s recent history (Figure 7), prehistory(Figure 8), and mythic history (Figure 9)
Where can they be found? Post offices are located in almost every city, town, hamlet, and almost every wide spot in the road!
Jung, Otto, Postal Stationery of Ireland, FAI, Vol. 30, 2012