When the final box-office figures are revealed after this closing weekend of the 2015 event, it will be unsurprising if Celtic Connections does not have a new record to report.

Anecdotal evidence, and personal observation, suggests that most gigs have been well attended, many sold out, and the whole fortnight-plus has had a really substantial feel to it.

That is significantly enhanced by the very high production values that are evident at every concert. The staging of Celtic Connections is a class act, which is why class acts want to play it. Anyone who attended the Music Of Craig Armstrong concert this week saw over a dozen extra musicians join an augmented Scottish Opera orchestra, a programme of linked cinema projecting and some snazzy Hollywood lighting in what was a lavishly staged one-off that defined what a festival event should be.

The reach of the Celtic Connections across the city is now well established. There is no other time of year when the city council's own venues - Glasgow Royal Concert Hall, the City Halls and the Mitchell - are as well used, but Celtic Connections feels just as important at Oran Mor, the Tron, the Arches, the O2 ABC and Glasgow Art Club. Regular venues like St Andrews in the Square and the National Piping Centre have been joined by select gigs at Queen's Cross Mackintosh Church and Platform in Easterhouse. That is some geographical spread.

The festival brochure boasts that it occupies 24 venues, which means counting the various spaces within the multiplexes of auditoria separately, but even a conservative count identifies at least 13 venues with a dedicated Celtic Connections role. And in most cases, you can be in no doubt of that communal identity once you are inside, with the festival logo projected on to stage backcloths.

Yet how evident is that to visitors to the city, or even to the many residents that the whole thing does not engage? There is very little dressing of the public realm or even the outside of the venues. To my mind the city should be screaming "Celtic Connections" to anyone walking through the centre and it seems somewhat peculiar that Buchanan Street, Sauchiehall Street and Candleriggs are not festooned with banners. I suspect the city marketeers think differently, but the ubiquitous People Make Glasgow advertising seems relatively vague and meaningless by comparison. Could some of the space allocated to that not be repurposed for something in which it is easier to take pride, and which might translate into ticket sales into the bargain?

That would surely be a very sound additional investment for public money, whose role is already crucial to the festival's success. Although Celtic Connections has a very good model of using visiting artists across more than one gig, in support slots and special programmes as well at the festival club, the artists' fees element of the budget must be enormous, and the support of Glasgow City Council and Creative Scotland is what makes the quality of the festival programme possible, anticipated record box-office returns notwithstanding. It is also what guarantees the substantial coverage that the BBC has given to the event, particularly this year, with all the extra publicity that produces too.

(And indeed the amount of space allocated to it by Herald and Times Group newspapers like this one, I might add.)

Since Scottish Power ended its association with Celtic Connections a few years back, the event has been without a title sponsor, which seems surprising given the national and international profile it enjoys. It does make one ponder the whole future of commercial arts sponsorship when such a demonstrable success lacks a backer. And if I were a corporation looking to spread my name through its music, I'd be less concerned with having my name above the title than I would about having it out on the street, as the banks have done at the Edinburgh Fringe and Festival Fireworks Concert. If Glasgow city does not grab that marketing opportunity, it is ripe for commercial exploitation.