Somewhere about the time I bought the Friends book and soundtrack, a strange compulsion kicked in - that nerdy urge to own everything even vaguely connected to a TV show, most commonly seen in fans of Star Trek and its ilk. What is, frankly, most bizarre is the sheer effort I had to put in to chuck my money after Ross, Rachel & Co. New York, to buy a T-shirt? For heaven's sake, what's wrong with these people? Do they not want to sell things? Although, to someone so obsessed, it's quite cool to be stopped in the street by people wanting to buy your T-shirt off your back ...
As with most things, the Brits are a bit behind the US. In an industry worth an estimated $104bn worldwide, Americans spend around $70bn on licensed products of one sort or another. (Europe spends around $13bn.) TV-related licensing is an increasing part of that market, but the UK broadcasters are catching up. In recognition of the eminent saleability of TV tie-ins, this summer sees the BBC's first "shops-in-shops", dedicated areas within chains such as John Menzies or WH Smith which will mainly feature children's products, but also include a BBC comedy zone, and will branch out into factual and drama spin-offs.
So far in Britain, merchandise has been centred on the lucrative children's market. At the TV spin-off Mecca which is the Warner Brothers Studio Store in New York, ER hospital scrubs (as worn by Drs Green, Carter and Ross) nestle alongside the Friends-wear. Yet over here, while there is a long tradition of little Britons growing up with Thomas the Tank Engine duvet covers and Postman Pat lunch boxes, for those over the age of 12, it's pretty much cold turkey once you've bought the video and possibly the book.
Notable exceptions are the magic "cross-overs" - shows that have both adult and child appeal. These rare breeds - including BBC Children's biggest success, Wallace and Gromit, and Nickelodeon's Rugrats - are usually animated and generally humorous, and are the nirvana of merchandising. The top- end gift products (alarm clocks, figures) sell to Dad, and the kids want the Thermos flask. Then there are the sci-fi-based shows, referred to as "cult" (which in telly terms now seems to mean, yes, we think we can flog some T-shirts on the back of it). Red Dwarf has warranted shelf space in HMV for a while now, though it pales beside the business done by The X Files.
Programme-related products are, however, small-fry when compared to the biggest television brand in the world, right up there with Marlboro and Coca-Cola: MTV, owned by the US media giant Viacom. MTV has been licensing its brand in Europe for just over two years and is now turning over several million pounds on merchandise alone within Europe.
"We started as a reaction to requests from viewers," says Julia Sadd, head of licensing and merchandising, MTV Europe. "People would see internal products, like bags and T-shirts, and phone up and demand to know where to buy them. We even had instances where staff had their MTV bags stolen from airport luggage carousels."
MTV discovered that its viewers expected merchandise in three areas: music, publishing and fashion. Beginning with a series of compilation CDs (one of which, MTV Raps, seems to be Germany's equivalent of the Now That's What I call Music franchise), the range has expanded through CD storage bags, CD-shaped greetings cards and MTV stationery to a newly- launched MTV clothing range, currently setting the tills alight in Top Shop.
"The brand is larger than the channel," acknowledges the company's vice- president of business development, Paul Chard. "It's the only case where that's true, and it's almost out of proportion. This means it lends itself to all kinds of spin-offs."
It also means that he can change the perception of the channel and create a new image by focusing on "bigger ticket items". Something to bear in mind as MTV prepares to relaunch into the UK, where it isn't exactly widely watched.
MTV makes a distinction between "more of the same" marketing (the book, tape, or video of the show) and what it terms "brand extension" (products related to the core business). Then there's "straight licensing", where Granada has recently ventured with a range of Coronation Street spin-offs (fudge, chocolate, diaries, cookbooks).
Breaking in isn't just a question of shoving product into the shops; as Granada found out with its Coronation Street spin-off video last Christmas, mistakes can be expensive. The cost of the promise to consumers that the special episode would never be aired - and its subsequent airing on ITV - is expected to run to millions in refunds to disgruntled viewers. Not to mention the damage to consumer perception of a favourite soap.
Further hazards lie in the minefield of rights clearance. As experts point out, a range of, say, EastEnders stationery would probably need to feature pictures of the cast - who may well have their own licensing deals. It's rare that broadcasters own all the rights in a show. One reason why kids' shows are easy to license is that puppets don't have agents.
Trade wisdom has it that there's one good merchandising opportunity in every programme, although if there's one for Newsnight it's not immediately apparent. The BBC cites Animal Hospital, its peak-time series hosted by Rolf Harris, which, on close inspection of the viewing figures, is disproportionately popular with pre-pubescent girls. They like to nurse sick animals. Hence a hugely popular range of injured soft toys, bearing the Animal Hospital brand, complete with bandages, feeding bottle and a paw that turns pink when you apply an ice-cube. Clever.
Those kinds of anomalies are sometimes seen when translating merchandise from one country to another. The holder of the BBC's commercial activities, BBC Worldwide, is currently reinventing itself on the grounds that customising product to its sales territories is the way forward. You may think that a mug is a mug is a mug, but there's no accounting for local differences.
Pingu - the animated adventures of a baby penguin - airs in the UK as part of Children's BBC aimed at a pre-school audience. In Japan, it's huge with teenage girls. There are more than 200 licensed Pingu products, many unique to Japan. Where else, after all, would you sell Pingu acne- prevention products or Pingu "sock glue"? Apparently it's something you need to keep your socks up if you don't have hairy legs; the Friends version is doubtless on the wayn