Roses are red

Roses are red

Violets are blue

Best not be single

In a world built for two.

Valentine's Day approaches. Cue frenzied searching of the doormat/Facebook/Twitterfeed among the lovelorn teens and tweenies. Cue hasty purchase of dodgy garage bouquets by male spouses. Cue an avalanche of cheesy adverts by restaurants, travel companies, jewellers and so on. You would astonished (or maybe not) by what salespersons feel able to re-brand as evidence of undying devotion.

For you, my angel, the winter tyres you've always longed for. And cue scurrying under the duvet for folks who find themselves inadvertently and reluctantly alone.

Yet Planet Single is not an under- populated quarter of the social universe. There are four times more solo households than in 1960, and in March last year, figures revealed that, for the first time, these outnumbered any other kind of living arrangement in Scotland. One-third of all Scottish roofs shelter a single adult. Unpack these figures a little further and you find the fastest rising single demographic is among 25 to 44-year-olds; a proportion driven partly by choice, partly washed up on the rising tide of divorce, and a smaller number, mainly men, who will never permanently co-habit.

Further up the age range, there is, unsurprisingly, a preponderance of widows. I joined that community still in my fifties, and promptly learned that, whatever the census figures might suggest, the world belonged to Planet Couple. That guy Noah has a lot to answer for. Suddenly, single men are wooed by hostesses looking for spare blokes round their table. Or just wooed. Their female counterparts are either filed under threat if they're young enough, or, after a certain age, presumed entirely self-sufficient.

What continues to bemuse me is how slow a consumer-orientated society and its sniffer dogs in marketing has been in recognising the untapped commercial potential of both the Bridget Jones generation and those of their elders also flying solo. Even outwith the annual frenzy of Valentine themed ads (and, as a woman once married to that not so rare species, a romantic Scotsman, I begrudge nobody their annual love-in) the advertisers routinely point their wares at Planet Couple.

Mini-break hotel prices advise their special offer is based on two adults sharing, and, although a few specialist holiday companies have broken the mould, the ubiquitous single room supplement persists. This is based on at least two false premises about customer base. One is that two same-sex adults who are not romantically involved will want to share; you get used to your privacy and personal space when you live on your own. And the other is failing to calculate that ditching the supplement would open up a large, new market.

This determined effort to play nuclear families in the face of all contrary demographic evidence also ignores the pink pound. A gay friend last week uploaded a picture of his hotel room, complete with heart-shaped sweets and red roses sprinkled on the bed and a welcome note to Mr and Mrs Bloggs, the result of his advising his Berlin hotel that he and his partner were there to celebrate their anniversary!

Supermarket chains too have been tardy in recognising that a rising army of customers of pre-prepared food would rather shop for meals for one than buy the larger variety and either freeze half or have the same menu two nights running. It isvery useful in an age of austerity to supply "dine in for two for a tenner" options. Similar imagination applied to those normally dining alone would be welcome, though "mains for one" are available in a limited range.

Jack Monroe, the single mum and food blogger, may help to change all this. Scooped up by one of the large chains as one of their advertising "faces", she has a lifestyle and a back story with which many young people can identify in the age of austerity, having had to give up her job with inflexible hours to care for her small son.

I don't know what she's cooking up on the blog for the 14th. But don't count on it being heart-shaped.