The Oscar Wilde trade cards I've seen are all contemporary with his two
American tours. The use of his image was intense but brief. Although there
are many different examples, they tend to be relatively uncommon compared to
other trade cards of the period, so I doubt any of them got extremely wide
distribution. However, from the 1860s to the 1890s, Dickens' image was used
more often. Twain's image was extensively used in advertising for a variety
of products from the 1860s to the end of his life: trade cards, cigarette
cards, playing cards, newspaper ads... all manner of advertising... I'm out
of town at the moment, so unable to provide a count of the examples I have.
I have a vague recollection of an article on Oscar  Wilde's image on trade
cards, or perhaps it was an article that included some discussion of Wilde's
image used on some cards; it may have appeared in the Trade Card Collector's
Quarterly (now defunct). I have a complete run of that journal, but cannot
check it until I'm back in my office.

Kevin Mac Donnell
Austin TX