In order to reinforce their brand, publishers carefully select fonts that strengthens their identity and is a statement of originality. 

Marfeel has performed exhaustive research - studying everything from background colors to letter spacing - to identify the ideal make-up of content that optimizes readability, enhances the user experience, and provides organic page flow. Through these investigations, Marfeel provides the best-suited typographies substantiated through analysis.

Moreover, loading other typographies can be very expensive to bandwidth and loading times. A new one can cause an extra load of 100KB that can delay rendering and work against a shared goal of providing instantaneous content. 

The default fonts Marfeel uses are also optimized for delivery and page speed. Apple and Google invested a lot of money to develop these default fonts that enhance readability and are designed to render very quickly.

There's significant quantitative and qualitative evidence from an aesthetic and performance perspective behind the typographies and fonts Marfeel recommends. Although the title and body font can be modified, Marfeel strongly suggests that publishers stick with the system defaults.