a4o.net
Three arbitrary letters ask a reader to memorise. Three letters with a preposition ask them to complete a thought, and people remember thoughts far better than codes.
A4O reads as analytics for operations, automation for organisations, or advocacy for others. The first is the most commercially obvious: operational analytics is a real software category with real budgets, sold to people running warehouses, fleets, plants and service teams. A three-character name stating the pitch is a neat asset there.
Fixed supply at this length, continuous demand from every company formed, and the .net keeps it accessible for a platform business where the extension carries no penalty.
Offers considered.