I found the first newspaper ads in La Presse, a French newspaper in Paris, for Sept. 15, 1836, at the Gallica Bibliotheque Numerique (digital archives of French newspapers). Here’s the image. The ads are for insurance, pharmaceuticals, job agencies, stock, travel, mustard, and various medical treatments. Yes, 176 years ago. Who thinks advertising is a modern idea? (Go to La Press at the Gallica Bibliotheque Numerique).
I went to archives of British newspapers and found The Spectator, Nov. 1711 had advertisements.
In the Spectator, see page one, left column, where the publisher talks about advertisements, and then lists a series of these on the right side. By these, he seems to mean reviews.
These however aren’t yet modern advertising: no logo, etc., and it’s not clear that people paid to have these placed in the Spectator. La Presse may be the first newspaper that was based on advertising revenue.
(Note: I edited both of these images to fit the page. To see the originals,, go to the links.)