Of course, it's nice to get a good book at a bargain price. Everybody loves a bargain. And the exhibition centre was a great vault of bargains.

Lifeline said an amazing 16,000 people went over the three days.

In we went not meaning to buy, out we came needing a mule to carry the sales to the car.

But the real, long-lasting satisfaction comes from knowing that an old technology is outwitting all the newfangled stuff that we were told was going to transform our world.

Printed books, didn't you know, were so old fashioned.

Clever people asked why we would lug around a tome the weight of a brick when all those words could be contained in a digital form probably no bigger than the freckle on your hand.

Except it hasn't happened.

Bricks and mortar book shops have been hit but we still buy printed books online - and they come through the post.

In the United States, the latest figures show that sales of printed books have been rising - 696 million of them last year, a rise of 1.3 per cent on 2017.

It's a similar picture in Australia. Books and Publishing reported: "According to sales tracking service Nielsen BookScan, 55.5 million physical books worth $1.07 billion were sold in Australia in 2017, up from 54.6 million books worth $1.06 billion in 2016."

In Australia, eBooks peaked in 2013 and have fallen as a share of book sales since.

The industry isn't out of the woods yet - but it's not in a death spiral either.

Who knows why? We all have our own reasons. We like holding a book. You can read them in the bath or in the bright sun by the pool. You can lend them to a friend. You know how many pages you've got left.

They just feel nice. They are comforting. Ever tried clutching a Kindle to your bosom?

Their stubborn refusal to die has negated another prediction made by those clever clogs of 20 years ago. When the internet was the newest thing, the fashionable view was that posting an item was very old hat. That, too, has turned out to be unfounded.

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It's true that Australia Post has just reported a fall in profits but that's partly because we don't write and send letters (and receive bills and those tedious official notifications) like we used to.

The days of penning thank you notes to Aunt Eliza for the pair of socks at Christmas have gone - but we increasingly send the socks by post, or get an online business to send them for us.

Parcels! They're booming. Revenue to Australia Post last year for delivering packages to our doors or to the four thousand or so post offices across Australia rose by 9.2 per cent to $3.18 billion. Revenue from the international parcel business also rose, up by 15.7 per cent.

It was the same the previous year. Letters slumped and parcels soared.

Of course, it's a challenge for post offices everywhere. In business speak, Australia Post chief executive Christine Holgate said the "double-digit shifts in both letter (down) and parcel volumes (up) underline the continuing operational and cultural transformation of our business - from being primarily a letters-focused business into a competitive delivery and service business".

There is a hoary old story that pleases those who rejoice in the survival of the old and trusted: back in the white heat of the space race, NASA was determined to invent a gadget that could write in weightless space. How could ink flow without gravity was the conundrum.

The American aeronautical agency threw millions at the problem, instructing its best minds to beat the Ruskies in the writing implement race.

So the story goes. But the Russians weren't so concerned - after all, they found that pencils worked perfectly well.

The story may be true. But whether or not it is, the lesson from the story stands up: don't write off old technology.

And don't believe those who forecast the future with certainty.

Think of William Orton who headed a telegram company writing off the new-fangled telephone that threatened his business: "This 'telephone' has too many shortcomings to be seriously considered as a means of communication."

Or film mogul, Darryl F. Zanuck, predicting that new-fangled television didn't threaten his business: "People will soon get tired of staring at a plywood box every night."

Futurologists get it wrong. In 1992, the New York Times asked if the printed book could survive a "world of video transmissions, cellular phones, fax machines, computer networks, and in particular out in the humming digitalized precincts of avant-garde computer hackers, cyberpunks and hyperspace freaks".

The death of the book is exaggerated. Rejoice.