Compatibility, Simplicity, and Cost.
Compatibility – To ensure the widest possible compatibility across MediaWiki servers, Real Obvious Alert is installed as an enhancement (not a plugin). Installing Real Obvious Alert is easy as 1-2-3 — Step 1) Upload the alert image; Step 2) Update common.css; Step 3) Create the MediaWiki Alert Template.
Simplicity – MediaWiki Templates are used to add “Alert” messages to a wiki page. Real Obvious Alert ensures a common look and feel of Alert messages for the MediaWiki site.
Cost – Real Obvious Alert is made available free of charge.