Would you put advertisement in your books?

[Nik]

I remember reading one of the bestsellers in Russian, mentioning at least 5-6 times along the book main hero brushing his teeth with a specific brand of toothpaste and drinking a specific brand of whisky. These were totally unnecessary details for the plot and oddly stood out causing me feel the author might've had some arrangement with these brands' distributors. Haven't encountered this in other books.
I can not know whether it's my usual paranoia or the author did close a promo deal, anyways: would you place advertisement in your stuff? Did you encounter similar instances?