What is a 300×600?
The 300×600 ad unit is an IAB standard ad unit with the dimensions of 300 pixels wide by 600 pixels tall. 300×600 ads are also known as a Monster MPU or Half Page Unit (HPU). There is also a special version of a 300×600 known as a Filmstrip, which scrolls through five different screens (making a total space of 300×3000).
The 300×600 ad can be run in it’s own ad slot, but is more commonly set up as a multi-sized ad slot along with a 300×250.
The 300×600 half page unit is a highly successful ad unit in terms of both performance and the eCPM it commands. However it has not made it onto the standard ad list yet because there are not enough sites that are designed to take it currently (it is on the IAB’s rising star list however).
The 300×600 ad size is usually placed on the side of a page, in the same place an MPU would be – with the extra height coming from below the 300×250 slot. It can also be run in a 160×600 ad slot with the ad slot expanding left or right to accommodate the HPU.
What it looks like
This is how 300×600 ads looks:
A Live Example (it may appear smaller than a 300×600 as it is a multi-size ad slot):
300×600 Advice for Site Owners
This ad unit is rarely used so it is best to have it as part of an expanding multi-sized ad slot with a 300×250, If you are unable to create an expanding ad slot, then it can also be used in a multi-sized ad slot with a 160×600.
If you have a choice about your site’s design then you should leave enough space underneath your 300×250 so that you can deliver this ad into the same ad slot.
This ad unit is often used as part of sponsorships, so if used it should be placed on every page.
300×600 Advice for Ad Buyers
This ad unit is usually very successful when used well so should be considered. It is however often expensive to purchase ad space in this size compared to other ad units.
300x600s are not very prevalent across the internet, so this ad unit should only be created when there is at least one specific site you intend to run it on.
Tip: A 300×600 is amongst the largest ad units available, so it should be used for interactive or video ads to get the most out of it.
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Author: Justin Driskill
Justin is the founder of The Online Advertising Guide and a freelance Digital Projects Manager.