By Gavin Stamp
Business reporter, BBC News, Liverpool
The Beatles are a vital part of Liverpool's tourism jigsaw
More than 40 years after the last performance in their home city, the Beatles remain as ubiquitous as ever in Liverpool.
Strolling down Mathew Street in the heart of the city, one can drink an espresso in the Lennon cafe and browse the shelves of the Original Beatles Shop.
After that, you can have a bite to eat in the Lucy in the Sky With Diamonds diner.
This tour is, of course, just an appetiser for a visit to the area's main attraction - the Cavern Club - the venue which the band made their second home and became synonymous with after being "discovered" there by Brian Epstein in 1961.
For anyone beginning to feel a touch of fatigue, help is close at hand.
In a couple of weeks, visitors will be able to rest their heads in the four star Hard Days Night Hotel - the city's most adventurous themed hotel yet - which is opening nearby.
Mathew Street is proof, if any was needed, of the remarkably potent and enduring global appeal of the Beatles and their enormous commercial legacy to the city.
"You could stick the word Beatles on anything and there would be someone out there who would want to buy it," says Jamie Ferguson, assistant manager of the Original Beatles Shop which has been selling souvenirs and merchandise since 1983.
Although he has sold themed kaleidoscopes and pinball machines in the past, many of his customers spend relatively little once they get there.
Many visits, it seems, are as much an act of pilgrimage as a shopping experience.
"If we just relied on collectors we would have been long gone. 90% of customers are tourists who want a memento of coming here. For a lot of them, a bag is enough."
There are thousands of people in Liverpool who owe their livelihoods to the band's continuing popularity and the seemingly unrelenting fascination with its musical origins and acrimonious break-up.
Those wanting to take a tour of key Beatle landmarks in the city are spoilt for choice.
The Magical Mystery Bus Tour - taken in a vehicle with appropriately psychedelic livery - will whizz you round all the favourite, iconographic locations in about two hours.
For those seeking a fuller itinerary, the Fab Four Taxi Tour promises three hours of excitement including the possibility of a rare visit to Ringo Starr's childhood home.
Deborah Kenyon, whose husband launched the business earlier this year, says they saw a gap in the market for a tour offering a more personal and relaxed experience.
"It has been much better than we had expected and we realize there is quite a market out there," she says, having secured more than 500 bookings since February.
"It still surprises me the level of interest in the Beatles."
Money may not be able to buy you love but undying love for the band continues to bring plenty of money into Liverpool.
Interest in the band's birthplace attracts visitors from all over the world and has contributed to a three-fold rise in overseas trips to the city in the past three years.
According to tourism agency the Mersey Partnership, about 600,000 people visit the city every year because of its unique association with the Beatles and spend more than £20m while they are here.
With celebrations for the 2008 European Capital of Culture - which will feature performances by the two surviving Beatles - getting underway, all looks rosy as far as Liverpool's status as the UK's magnet for music tourism is concerned.
But underneath the surface harmony, there is the odd discordant note.
For some, the understandable focus on the Beatles has obscured the legacy of the wider Merseybeat pop movement which continues to shape the city's current music scene.
An exhibition at the Liverpool World Museum later this year, examining the impact of artists ranging from Billy Fury to the Zutons as well as historic venues, seeks to rectify this.
But a more serious tug-of-war seems to be going on over the ambassadorial role that the Beatles play in attracting visitors and this may be harder to resolve.
Despite the success of recent years, some fear the city is not doing nearly enough to exploit the Beatles brand to its commercial advantage.
"There is no screaming and shouting that we are the birthplace of the Beatles and I think that is unfortunate," says Jerry Goldman, director of the Beatles Story exhibition and shop which attracts 200,000 visitors a year.
Civic leaders do not want to see other music legends eclipsed
He feels the city is missing a trick by not putting the band at the heart of its marketing strategy as a sort of neon sign to alert the world to its unique place in cultural history.
While evangelical about the wealth of cultural assets on offer in Liverpool, he is concerned there is no "clear message" about what makes the city different from other competing regional metropolises across Europe.
"You need a hook. Mention the Beatles and everyone still comes running," he says.
So why this reluctance to put the Beatles centre-stage?
"It started to happen for a very little while but then people started to shout 'there is more to Liverpool than the Beatles' and they lost it. There are people who have this attitude that we want to look forward rather than backwards and the Beatles is looking backwards."
Visitors to the exhibition are up 23% this year and a £1m expansion - which will triple its size and add many new features - is expected to boost revenues by 30% in 2008.
This growth is testament to the enduring interest in the band, Mr Goldman believes.
The Beatles' capacity to generate hard cash seems as undiminished as their ability to win over new generations of adoring fans.
"The music is known and loved by kids of all ages. That is what is going to keep the Beatle industry going for a couple of more generations."