Bibliothèque Nationale de France: posters from the Grands Magasins

There is a wealth of ephemera (under Images) in Gallica: Bibliothèque Numérique. The Bibliothèque Nationale de France often tweets topical result sets from Gallica. This screen shot came from one such tweet relating to the first day of the French sales.
You can display results as a list, as 'normal display' (image + record) or as  a 'mosaique', as in the screen shot. In this display, the records pop up when your mouse hovers over an image. A search for 'publicité' yields 2322 results: mostly printed ephemera with some photographs, including shots of hoardings.You can search within the results, e.g. 'bains', 'bicyclette' or limit by date, artist, language, etc. and you can save the results to your 'espace personnel.'
Other useful terms are documents iconographiques, adresse de marchand (trade card) billet (ticket), affiche (poster).
A wonderful way of surfacing ephemera within the BnF.

(C) Bibliothèque Nationale de France