# Advertisement Loading Strategies
The loading strategies explained next are configured in the Tenant's twister.json file.
# OnScreen
Ads with this strategy load all at once and straight away once the page is loaded.
This policy increases the ad requests that are made. However, this can also decrease the value of the ad spaces themselves since the viewability rate and CTR are normally much lower. This is an interesting setup when a big part of the inventory is sold directly and campaign performance is not the main KPI.
# OnScroll
Ads are displayed as the user scrolls through the content and the viewport comes near the ad position.
This setup can reduce the number of total Ad Requests although it substantially increases the quality of the impression. Since an ad is only loaded if it's about to appear on the viewport, the probability to click is maximized and the CTR goes up.
# OnInteraction
Ads will enter a loading queue as soon as the user interacts with the pageview, for example, a scroll interaction.
The queue consists of a FIFO scheduler that will execute while the processor is idle.
WARNING
ANY change on the loading strategy of a placement/adserver must be approved by PI team
# Default strategies in Marfeel
On Scroll is the default loading strategy for all placements and adservers with the following exceptions:
First inline position or
inline_1uses On Screen by default.interplacement uses On Screen by default.stickyplacement uses On Scroll by default. In this case, the strategy is equivalent to On Screen sincestickyis always in the viewport.
Adservers that load On Interaction by default:
TIP
To check the current loading strategy of an existing ad in a Marfeel tenant, inspect the element in the browser and search for the data-loadstrategy attribute.