Web advertising: sizes, types and costs

March 04, 2014

Web Advertising: sizes, types and costs, AM-Insider article by Sarah Ritchie

The minute you get involved with a "digital campaign" you will be dealing with digital ads. Once you understand the different ad types, and how to get them to market, the murky haze of "digital" starts to become a little clearer.

Here are some key points to note about digital ads:

  • Sizes are specified in pixels (not mm, cm or inches); "px" = pixels.
  • Resolution is 72 dpi.
  • You will usually be required to meet a (small) file size requirement. Your designer should know how to save or export the ad artwork for use on the web.
  • You may need to supply files for a website, mobile device, app or social media (e.g. Facebook, YouTube). You will need to understand the file sizes and requirements for each instance. Ask as many questions as you need to, right at the beginning!
  • If you are placing retargeting ads you will need to create two sets of creative (see below).
Who will place the ads?

You (or your client) will need to choose an "ad serving company". This is a company specialising in placing ads on websites. They will serve ads, count the number of impressions/clicks for a campaign and choose the ads that will make the advertiser the most money. They will monitor the progress of different advertising campaigns, tune and optimise based on results, and provide detailed reporting for you to assess the all-important ROI (return on investment). They should also give you a detailed post-campaign analysis.


Static or animated?

You can supply your digital ads in one of two ways: as a "static" ad (e.g. JPEG or PNG format) or "animated" ad (e.g. GIF or SWF).

It is widely acknowledged that animated ads will achieve a higher click-through rate than static ads, but it obviously takes additional operator skill (and time and money) to create the animated file, and so you have to make the appropriate decision for your project.

Flash format: Although it is still possible to create animated ads using Adobe Flash (SWF format), the main thing to remember is that Flash ads will not show on any Apple devices (iPhone, iPad, etc), therefore you effectively wipe out a significant portion of your potential viewers.

Flash files are usually smaller and of better image quality than animated GIFs. You can add sound, video, more colour options and interactivity, but they also require an added browser plugin to view.

GIF format: Animated GIFs offer a simple cycling animation, and are usually less complicated to produce than SWFs. You can include transparency without having to touch the code.

GIFs may have a limited colour palette and be of lower quality output than SWFs, but they are compatible with older devices, all portable devices, and browsers - which could be the deal-clincher.


Naming your ad files

There is no standard way to name your ad files, but it would be wise to include the job number, advertiser name (e.g. the name of your client) plus the width x height.


Retargeting / Remarketing

You may need to create two different versions of your ads - one for your standard marketing message and one for a "retargeting" or "remarketing" (REM) message.

Retargeting involves a tiny bit of code (JavaScript tag) being embedded in your client's website (and/or microsite, landing page, Facebook page, iFrame, etc). The code creates a list of people that visit the site by placing anonymous retargeting "cookies" in their browser. This list allows your ad serving company to keep track of people who visit your site, and displays your retargeting ads to them as they visit other sites online. The retargeting version of your ad will "follow them around", so to speak.

Retargeting ads should have a stronger call-to-action and promote an offer. For example, the first time a person sees your ad the message may be slightly mysterious, or it may say "click here for more details", whereas a retargeting ad may say "buy now" or "act now". You know the viewer has already been to your website and knows what you are promoting - retargeting capitalises on this.


Homepage takeover

A homepage takeover is a collection of ad units displayed for a day on a publisher's homepage. Different ads can be combined for page takeovers (e.g. background skins, interstitials, mastheads, etc).

Advertisers have a 100% share of voice on the homepage, as no other ad is shown. Here is an idea of the cost (in USD):

  • $400,000 to $700,000 on some websites with huge traffic, such as Facebook, YouTube and Yahoo.
  • $200,000 to $300,000 on media websites such as ESPN or The New York Times.
  • At least tens of thousands ($) for most popular websites.

Some points to bear in mind with homepage takeovers:

  • They are not targeted, as per usual digital campaigns.
  • The rate card price is completely negotiable.
  • It's your campaign, so you need to keep control over the creative.
  • The best takeovers blur the line between the creative and the content, and seamlessly integrate the brand's message with the publisher's style. Here is a great example.
  • Some publishers will allow "dayparting", where you can run the takeover for 6 or 12 hours, rather than the whole day - great for smaller advertisers to punch above their weight.
  • Implementing a takeover is a complex process. Play nice with the publisher!
  • A takeover should be part of a larger media strategy for the greatest success.
  • Be aware that a lot of publishers set their homepage to "auto-refresh" every few minutes. This can lead to inflated impressions (meaning the advertiser may pay more for their campaign), and it can also create havoc with the creative. Best to ask the publisher to turn off auto-refresh while your campaign is running.
  • There are no standard specs for takeovers. Always as the publisher for the latest specs before starting the creative. Here is an example of specs provided for the TVNZ website homepage takeover.


Cost models

There are numerous ways that an advertiser may be charged to run a digital ad campaign. Here are three of the most common models:

CPA (Cost Per Action): All the risk is assumed by the publisher. The advertiser only pays the publisher if someone clicks AND completes a transaction.
PPC (Pay Per Click): The most common form of online advertising it tends to suit both the publisher and the advertiser. The advertiser pays when someone clicks on the ad, but they do not have to complete a purchase for the publisher to get paid. For this type of ad, getting keywords right is extremely important.
CPM (Cost Per Mille): Also known as CPT (Cost Per Thousand) or cost%. The advertiser pays for exposure based on visitors to the website and eyeballs on an ad. Here is a handy CPM calculator to help you determine costs.

As you can see (from the chart below) there are many different, standardised, ad sizes (and this list is by no means exhaustive). It still pays to ask for sizing confirmation for every new digital job.

Name Width (px) Height (px)  Aspect ratio
Medium rectangle 300 250 1:2
Square pop-up 250 250 1
Vertical rectangle 240 400 0.6
Large rectangle 336 280 1.2
Rectangle 180 150 1.2
3:1 rectangle 300 100 3
Pop-under 720 300 2.4
Full banner 468 60 7.8
Half banner 234 60 3.9
Micro bar 88 31 2.84
Button 1 120 90 1.33
Button 2 120 60 2
Vertical banner 120 240 0.5
Square button 125 125 1
Leaderboard 728 90 8.09
Wide skyscraper 160 600 3.75
Skyscraper 120 600 5
Half page ad 300 600 2


This illustration is reduced in size. See actual sizes here.
Size information courtesy of Wikipedia.


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