There are different types of Banner formats that can be designed, such as in .JPG, .PNG, .GIF, Flash and HTML5. Choosing which Banner is best for is more so of what kind of advertising you want to do where and what is allowed.
Here is a list of different sizes in pixels that Google for example will let you use for PPC.
320 × 50 Mobile leaderboard
320 x 100 Large mobile banner
468 × 60 Banner
728 × 90 Leaderboard
250 × 250 Square
200 × 200 Small square
336 × 280 Large rectangle
300 × 250 Inline rectangle
120 × 600 Skyscraper
160 × 600 Wide skyscraper
300 × 600 Half-page ad
970 × 90 Large leaderboard
240 × 400 Vertical rectangle
970 x 250 Billboard
300 x 1050 Portrait
When online banner ads first came on the scene, the concept was revolutionary and changed the face of advertising. Despite the grand entrance, however, banner ads became seen as a pest, bombarding users, and causing them to actively avoid them. Several years, and many tests later, best practices for banner advertising have been established to guide marketers towards creating successful campaigns that encourage users to actually click on the ads. Banner advertising is now a proven, and highly effective way to bring targeted traffic to your site, or landing page.
There are three key areas to focus on to ensure your ad campaign is a success:
Define what your overall goal is.
What do you want your marketing campaign to achieve?
Define the role of online within the bigger picture
How does the online portion of the campaign fit within your overall media plan? e.g. Is the role to drive direct leads, or to build brand awareness by complementing your offline efforts?
Set your expectations.
What results will make you happy at the end of the campaign?
People may be influenced by your ads even if they don’t click on them. If your ad complements what is being done offline, it can be extremely effective at making a lasting impression with your audience, which can be measured as part of a larger brand study encompassing all the campaign’s touch points.
Measuring clicks is important if you’re looking to generate traffic as clicks identify how many people went to your website. But don’t forget, some people won’t click the ad, but will visit the site anyway because of an offer they saw in your ad.
Clicks and traffic aren’t everything. If your goal is to generate qualified leads, you must measure how many clicks converted (i.e. filled out a form, subscribed etc.) once they got to your site, or how many people called you after seeing your ad.
Align creative strategy to campaign objectives
If you’re building a banner to generate leads, create strong messages that drive direct response. e.g. offers, calls-to-action (CTAs). To win the conversion, you need to tell users why they should click your ad. What is the immediate benefit to them? Words such as ‘buy now’, ‘sale’, or ‘free’ will tempt users to click on your ad.
If you’re building banners to lift brand awareness, think about leveraging creative from your other brand assets to ensure that there is consistent messaging between your online banners and your activities offline. Think about the way your banner ads represent your site – they should be an extension of your existing brand. Do not bring new brand elements into a banner ad as you may confuse users and miss out on extra clicks gained from brand recognition.
Remember, brand lift doesn’t happen in being exposed to a brand once, twice or even three times. Sometimes a consumer has to be exposed to an ad up to nine times before impact is made. Linking online and offline creative is more likely to impact brandlift sooner.
Keep your message straightforward
Use the limited space wisely to promote the one message that you want consumers to retain. Cluttered ads are a sure fire way to put off potential traffic. If you want to advertise more than one product, or have multiple CTAs, run multiple ads, do not try and fit it all into one.
Best practices for ad position are to have your banner ads within the page content, in the heading, or in the right hand column for maximum effectiveness. Above the fold ads perform better.
If you have multiple banners on a page (e.g. homepage takeover), think about how each banner can deliver to objectives differently. Too often advertisers take one creative look and one message and adapt them to different formats. Break from this mold to put a compelling message in the Header, put a complimentary message in the Big Box, put supporting imagery in the Skyscraper.
Use your creative imagery to cut through the clutter
Webpages are busy places. Your banner ad will be competing with several other components on the page for the user’s attention. You have limited space, visibility and size, therefore keeping the ad to the point is critical. Best practice is to use approximately 2/3 of the available space for the message, and the remaining 1/3 for the CTA. Avoid making the message too long.
Your creative needs to stand out from the rest of the page. Color and imagery are key to grabbing your audience’s attention. Beware that if you are running the same ad on multiple websites, what might look good on one site might not look good on another site. For the CTA, bright colours and clickable shapes are essential. Avoid banners with white backgrounds as these can get lost in the website.
Keep your audience top-of-mind
Remember, users visit a page to see content, not to see your ad. If you want to make an impact, you need to figure out how to detract them from their original objective (i.e. look at the page’s content) and engage with your ad.
Provide contextual messaging. Make sure that you’re pushing your ad at the right time, in the right place and to the right people. You could have the best banner ad in the world, but if it’s out of context, your campaign will not be successful. e.g. if your ad is on a site where the user has just looked up a Prius Hybrid, you wouldn’t push a pick-up truck ad.
Track, measure, monitor and adapt
Why you were running the ad in the first place. Was it for brandlift, traffic or leads? Review your metrics to determine whether or not you are meeting your objective. Remember, if you decided that brand lift was your main objective, don’t be surprised if you didn’t get any clicks!
Don’t wait until the campaign is over to review whether or not it is working. Online tools such as Google Analytics provide real-time feedback as to what is working and what isn’t, so you can tweak your campaign. Simple adjustments (e.g. background colors, imagery or one word in the message) can make a major impact to the success of a campaign.
Avoid these two major mistakes:
Building an ad that doesn’t meet IAB standards. Websites have built their ad slots to these standards so if you’re not building to these specs, your ad may not make it onto your site.
Your creative is great, your call to action is aligned with your objectives, but your landing page doesn’t fit with your call to action e.g. A French banner ad links to an English landing page.