To each his own 
His fanbase has grown further with THE GREATEST SHOWMAN. We now know that the movie musical, despite the critical reaction, became the Cinderella story in the USA and worldwide box office.
As for the music --
Per RIAA certification --
https://www.riaa.com/gold-platinum/
If you trawl through it, at least for 2018, here are some interesting accomplishments for Hugh and his co-stars:
*The soundtrack album was certified as 2x Platinum ( at least 2 million in sales) by August. No update available since then. This is for the USA alone.
*Platinum singles ( at least 1 million) for This Is Me/RewriteTheStars/TheGreatest Show/AMillion Dreams//Never Enough... and Gold singles( at least 500,000) for The Other Side, Come Alive, and From Now On.
In the UK, the soundtrack has reclaimed top spot on the Official Charts ( 23 weeks as #1, including the past and current week) with 5x Platinum ( at least 1.5 Million in sales). Btw, his Tour includes 5 shows at the O2 Arena in London, 3 shows each at Manchester and at Birmingham.
https://www.officialcharts.com/chart-news/the-greatest-showman-scores-christmas-number-1-album-with-strongest-sales-week-yet__25236/?fbclid=IwAR0TxXLlUdoU4WGwxam7lKkwUmyWeI6B9NcZ0jIxWpRes4zd1-OnnWpXQ_Q
It is interesting to note that according to Pasek and Paul, they suggested to Hugh to look up Liz Caplan for singing lessons/techniques for the TGS film project, which led to a more contemporary/pop sound (which was what the soundtrack demanded). Prior to that, Hugh's longtime voice teacher was Joan Lader.
While the Music Tour will include from both stage and film musicals that he has been involved in, it looks like he is exploring performing with other stars of pop music ( if they agree to join him) such as Pink, Kelly Clarkson ( both of whom did covers for "TGS Reimagined" ). But he also says that Keala will appear in some of the shows. Who knows if the pop stars can join him for some of his shows ( as some, like Pink, will have concurrent music tours). For the Hollywood Bowl, he says that James Corden has tentatively said Yes to join him, presumably for some lighthearted moments ( Remember their Crosswalk Musical featuring The Greatest Showman?).
Whoever else joins him to spice up the show, Hugh will definitely be enough attraction for ticket sales to go well as the dates come closer. Warren Carlyle ( with whom he has worked since Oklahoma! in London) is putting the show together, presumably with some assistance from the choreographer of TGS, Ashley Wallen, as the latter posted photos of their rehearsals for the TODAY show. Also, one of the most applauded dancers in the movie, Mishay Petronelli ( the albino lady who danced up a storm in From Now On) was part of his backup dancers at the Today Show. So, it will not be all singing - the show will feature both singing and dancing!
Updated On: 12/22/18 at 07:05 AM