Absolutely clear that mobile appears to be the main source for content consumption in the near future. It is in-app time what seizes the mobile web world mainly. This must be a good sign for advertisers. But, as everything else, it has its own advantages and disadvantages which influence both environments equally. If you depend on the budget only, then it is extremely important to study the pros and cons in details to make a right choice.
The following points should be taken into account above all others: reach, engagement, conversion, budget, ad blocking, etc.
Reach — Mobile Web
It is evident that anyone, who owns a smartphone, uses a web browser on the phone, considering it to be the most convenient way to find interesting content. This happens because web browsers hold access to all needed information by itself. Thus, your ad will be more readable through the mobile web, which is more popular among customers.
Apps are not so convenient as they seem to be. Customers should constantly download and update them to work with their content uninterruptedly.
Engagement — In-App
When surfing the Internet and visiting web pages, any ad can be irritable and unwanted for users. But apps are a perfect environment for ad realization, where it can be performed quite smartly. While using in-app, you call attention to the interest of your advertisements rather than to the number of clients.
Conversion — In-App
Why? High conversion directly depends on great engagement.
Targeting — In-App
While getting the application, the user provides specific data in real time.
Budget — Mobile Web
The applications are definitely higher in price because of better engagement and conversion. When using mobile web, things are in a different way.
Ad Blocking — In-App
In the context of ad blocking, web browsers are more vulnerable and inconvenient than the in-app environment.
Tracking Options — Mobile Web
It is profitable for advertisers to target those people who use the mobile web because of its easy tracking by S2S or cookies.
So, weigh all pros and cons and compare them to the expected results before making a final decision.