Well, to be frank, we have served over 1,000,000,000 ads over the past decade, and have not served AdSense directly in many years (we don’t like Adsense for many reasons), so let’s look at this “ad serving” from a high level view, from the perspective of what is going on now, in display advertising.
Then, they provide the publisher an
ads.txt entry this days and they will serve ads to the publisher from their ad network based on the site category and subcategories, not from a crawler (like the Adsense crawler).
This is the rule these days, and not the exception.
The same is true for video content and video-based ads. Our video partner sells ads for our site based on the context of the site, in a brochure, not based on a “crawling robot” looking for context.
In fact, we have not served ads for years from any ad network which depends on a crawler to classify a site; especially for passback tags. Passback tags always work best when the context his hard-coded into the ad network, versus derived from a crawler doing classification.
It is always hard to get relevant context from passback ads (tags).
My experience from a publisher perspective who has served well over 1 billion display ads over the years is to not use an ad network which develops context context from a crawler for passbacks ad networks.
It is best, based on my experience publishing ads over the last decade, to use passback tags based on hard-coded context, for example, if I have a tech site, and I want to serve passbacks to India, then I will use passback tags of tech interest to techies from India.
We used Adsense maybe 15 to 10 years ago, and for the past decade I cannot recall when we served AdSense directly. AdSense is not really a great way to generate revenue, in my view.
Adsense does develop context from their crawler, so in general, if your tag is not a nested IFRAME tag (an IFRAME passback tag within an iFRAME tag), you will be fine with IFRAME tags.
Some Advantages of IFRAME TAGS
The browser allocates some space for an inline frame beforehand and takes this into account when rendering the document.
Iframes implement the cross domain origin policy which can be useful for pulling in sites / content/Ad from other domain names and they are also relatively safe and that is why most of the web advertising solutions are based on iframes
If contents to be loaded first and then Ads , it can be done using Iframe.
rame helps in improving performance.
Iframe loads independently from other components on the page.
An iframe tag has attributes “height” and “width,” which allows the designer great latitude with dimensions and format like 300×250 , 728×90 depending on the Ad size.
Iframe tag can appear anywhere on the page and several iframes can be added if wished to.
Some Disadvantage of IFRAME TAGS
Iframe tags may cause accessibility problems.
Iframe tags are not supported by all the browsers and can display them improperly or even can serve blank.
A key reason for using iframe in web advertisement is security in cross domain support but performance is not perfect.
Iframes can not be seen by many handheld devices.
Iframe have been known lower SEO, at times.
Advantages and Disadvantages of JS Tags:
- Can add this later if anyone is interested.
Supply and Demand
This is the year 2020. The number of web-site supplying advertisers with ads has grown exponentially since 2000. The supply for ads has far out driven the demand. The means that for most sites, the ones who are here talking about setting up ads on Discourse, it is not likely they are going to get premium ad traffic unless they have a strong demand and an established niche audience.
Every techie and his sister can publish ads on their blogs and forums in the year 2020 and they do. This means that the supply will continue to outgrow the demand for display ads into the future. Most niche sites will have a hard time to generate ad revenue from a new site until they become well established.
Discourse and Crawlers
Discourse does not serve the SPA to crawlers, so this means that adbot crawlers will also not see the SPA and the full implications of this have not been “third party, objectively” analyzed (by an independent third party), to my knowledge.
If you run display ads, you will have issues on all SPA because of how the pages “do not reload” and this is an issue with JS tags and IFRAME tags; there needs to be better plugin code for SPAs to optimize all types of third-party tags.
We have not serve Adsense for many years and have no plans to do so in the future; so the point of how Adsense gains context is moot for us. For others, It’s better to run working IFRAME tags than to pull your hair out trying to fight SPA issues serving third-party script tags and CORS headaches, IMHO.
Crawl before you walk. Walk before you run.
Hope this helps.
PS: Sorry for any typos, my wife is waiting by the door and want to go shopping before it rains!