As you may know, the Government of Canada is THE biggest advertiser in the country. Their adds are all over, TV, radio, magazines, national newspapers, local daily's, local weeklies and now the Internet.
The Government of Canada has been on the Internet for a while. When I worked for a government information holtline in 1997, the presence was already quite impressive. Fast forward 9 years and they are spending some serious money on some seriously effective web advertising.
Case in point, information on what you can bring on a plane. I asked a couple of colleagues who had recently flown and got some incomplete answers. I had made a note that I needed to research it. Than a day later, a clever banner add on a Yahoo news site that gave me all the info I needed without even going onto the government site. Just put my mouse over it and got all the info needed.
As an attention grabber, I give credit to whoever came up with "CLICK HERE TO LEARN THE LANGUAGE BEFORE THEY DO, Government of Canada". I though I was going to have to learn Spanish or Mandarin. Turns out I only needed to brush up on my drug knowledge to have tweens.
Both are very good examples of effective advertising using banner type adds. So Yahoo! and Government of Canada, give yourself a pat on the back.
On the other hand, had I typed "what can I bring on a plane" in my Google search bar before heading out the airport, I would have learned everything I needed know. "Tweens and drugs" also gives plenty of information to read. That pretty much summarises advertising, it is completely useless and essential at the same time.