As mobile Internet has developed, user time has become fragmented, and the competition among media for user attention has become increasingly fierce.

For users, advertising is an accessory to the APP, not a necessity. The APP must monetize advertising on the premise of not affecting user operating efficiency and fully respecting user experience.

Advertising placement is essentially an infringement on user rights, but the media can make many adjustments in advertising design and strategy to reduce users' negative emotions towards advertising. For example:

• Add the words "preloaded on Wi-Fi" in the ad to make it clear to users that it does not occupy their data flow and does not incur any charges.
• Add more controllable elements to ads, such as countdown, disinterest, close, etc., to give users the power to provide feedback and take action;
• Add a setting to turn off personalized advertising in the personal center or privacy management, allowing users to decide how to use their data;
• …

But on the technical level, the media's advertising material loading mechanism is an important factor affecting user experience and advertising effectiveness. Problems such as low ad pixels, misaligned display, non-loading or slow loading will give users a poor user experience and waste exposure opportunities and potential conversion opportunities.

This article briefly summarizes the nature and description of the ad cache mechanism based on the ad display process, and provides a reference cache strategy for some ad slots.

1. Advertising display process

▲Bidding advertising display process, picture from the Internet

Some of the interpretations are as follows:

• Filter conditions : Preconditions set by the media, advertising requests are initiated only when the conditions are met. For example, no ads will be shown to new users within a certain period of time (new user protection period), and users will only be shown a certain number of ads within a certain period of time (ad frequency control).
• Ad source response : The ad source is the channel (DSPSSP) to which the media is connected. If the user tag information meets the channel's directional needs, the response means participating in the bidding.
• Time limit : Usually, the time limit = user dwell time - 1s, that is, the total time consumed in downloading and loading advertising resources should be less than the user dwell time.
• Bottom-layer display : bottom-layer ads, which are ads displayed when there is no ad request. It is mainly aimed at advertisers who pursue quantity rather than quality and low prices, or for media promotion of their own brands and activities.

To optimize the loading of ad materials and increase the ad display rate, we first need to clarify the ad display process. In the above flowchart, the following four conditions must be met to complete an ad display for a certain user:

1. The user meets the request filtering conditions, and the media publishes an ad request: This condition is related to the media advertising commercialization strategy, including new user protection and ad frequency control, and mainly affects the number of ad requests);
2. The user meets the demand-side directional requirements and has advertising sources participating in the advertising bidding: this condition is related to the number and quality of channels that the media connects to, and mainly affects the number of advertising fills);
3. The time taken to download and load advertising resources complies with the time limit;
4. Advertising resources loaded successfully: 3 and 4 are both key links in advertising display. The media can optimize them through technical means to affect the final number of advertising displays).

2. Ad caching mechanism

In order to increase the number and display rate of advertisements, the common solution in the industry is to build an advertisement cache mechanism to "preload" the advertisement resources of the advertisement slots or use "cached advertisements" for display, thus saving download time and avoiding the risks of real-time downloads (download failures caused by poor network environment and sudden failures), thereby increasing the speed of advertisement resource loading and the success rate of advertisement loading.

Do the advertising resources of all ad slots and ad sources need to be cached?

This is not necessary. Building an ad cache mechanism requires further clarification of control conditions, which can be divided into the following three aspects:

1. Object Control

That is, determine the objects of advertisement cache and cache only specific objects to reduce the cache workload.

1) Advertising source

Determine which ad source channels can display ad caches. Different ad source channels have different request mechanisms.

2) Advertising space

Determine which ad slots need to be enabled for ad caching, generally ad slots that support large-volume creatives.

3) Advertising creativity

Determine which types of resources need to be cached, generally advertising creatives in the form of animated images, videos, etc.

2. “Time and Space” Control

That is, determine the storage time and space of the ad cache to reduce unnecessary space usage.

1) Number of cache entries

Limit the cache quantity of each ad slot to reduce unnecessary cache accumulation.

2) Cache validity period

Set the automatic cache clearing time, usually x natural days or x hours.

3. Condition control

That is, determine the timing of ad caching, reduce server resource consumption, and cache more intelligently.

1) Preload ads

For example, when the banner ad on the homepage is displayed, the pre-loading cache mechanism of the ad position is triggered and it is displayed after entering the homepage.

2) Hit cached ads

If an ad source wins the opportunity to display this ad and the cache pool already has the ad, the display will be triggered.

3) Bottom cache ads

If no ad source responds with an ad, the cached bottom ad will be displayed first.

4) The request time interval has not arrived

If the request time interval has not yet arrived (that is, the request time is too long), the cached ad from the last exposure will be displayed by default.

3. Cache strategy for each ad slot

The following is a list of caching strategies for some ad slots in the industry compiled by AdBright:

1. Information flow advertising

Determine your caching strategy based on placement:

The first one in the information flow is cached when the APP is launched for the first time;

Other positions in the information flow can be cached in the first 70% of the ad positions (based on screen size evaluation).

2. Splash screen ads

There are currently three cache strategies:

1) No caching, real-time acquisition of requests and display of ads, but this strategy requires extending the display time of the startup page;

2) When the APP is launched for the first time, multiple requested materials are cached but no ads are displayed. When the APP is launched again, an ad request is initiated. If the cached materials match, the ad is displayed.

3) When the APP is started for the first time, multiple requested materials are cached but no ads are displayed. A scheduled task is used to update the ad materials when the APP is started, and the cached ad materials are displayed when the APP is started again.

3. Banner ads

Cache when the app is first launched.

4. Interstitial Ads

There are currently two caching strategies:

1) Node Cache

That is, pre-request and load ads in the front-end process of the ad display node, such as the interstitial ads displayed when the cache is paused after the user plays the video.

2) Chain Cache

That is, after the previous interstitial ad is closed, another interstitial ad is preloaded.

5. In-film advertising

Determine your caching strategy based on placement:

The previous video can be pre-requested and loaded when the app is launched and when the previous video is ready;

Mid-post and post-post ads are preloaded a fixed time before the ad is displayed.

6. Incentivized video ads

Similar to interstitial ads, there are currently two caching strategies:

1) Node Cache

That is, pre-request and load ads in the front-end process of the ad display node, such as when a user has only one life left in the game.

2) Chain Cache

That is, after the previous rewarded video ad is closed, another rewarded video ad is preloaded.

Author: AdBright

Source: AdBright (AdBright01)