Not sure if it's been mentioned but just generally market the club better, I unfortunately through work see a lot of the various stuff United put out and they make such a massive song and dance about literally anything they do whereas we don't.
For instance looking on the shop website there's the new training gear for this season available now as well as some new casual T Shirts and Polo shirts yet I've seen nothing on the club website, or social media to tell fans.
Also the 6 match bundle deal as far as I can tell has largely only been advertised at matches which means most people seeing will probably already have a ticket for the games. Advertise on Social Media, in the Star, I remember seeing adverts for Season Tickets on billboards a few years ago. Surely any expense would be covered if 1% of people who see the ads buy the 6 match bundle?