Sorry to inform you, your post is a little out of date.
This statement is factually incorrect:
| So now you know the secret. You must create a copy of your ad in EVERY available image size. This way, every website that can display your ad, will display your ad. |
As of May 5th, 2015 it is no longer necessary to create all those different image ad sizes. If you have banners ads covering 300×250, 728×90 and 160×600, Google will automatically resize them. Those 3 ad sizes are all you need to create to get your ads displayed in nearly every size format and nearly all websites on the Display Network.
Also, AdWords has a built-in tool, the Ad Gallery, for quick and easy display ad creation. Creating effective display ads in all the needed formats using industry-standard image ad templates is not only quick and easy, but all templates in the Add Gallery are free.
