Question: how many ads we see in a day? 

Answer: The statistic I usually hear people cite is around 3000 a day (print, TV, radio, everything). This link has some really good sources/info with other stats: http://answers.google.com/answers/threadview?id=56750\n\n(ironic, ain't it, to be using answers.google.com?)
This question from the Yahoo Q&A forum is categorized in the topic: Entertainment & Music