Let us pretend that the following year the event had grown, it was better than the previous year and perhaps the attendance was really quite good. But even though they could have told everyone this real figure, it was less than last year's announcement - and everyone could see there were more spectators for the second year. So instead, perhaps they might have taken the previous year's 'figure' and added a bit. And so it went on for many years.....

Over on the Post's Lifestyle blog Jon Bounds has been commenting on the figures for the Conservative Party Conference in Birmingham. He makes the interesting point that " the Tories brought £20M to Brum .... The Rotarians are also estimated to bring £20M despite there being twice as many of them, well I suppose they do drink less," he said.

His piece is well worth a read - it's one of those spot-on blogs that has many serious points among the humour.

Now you've read it, let me expand his analogy of Birmingham as giant licensed premises with Mike "global boozer, local barstool" Whitby as landlord.

One benefit Jon has overlooked is the number of people who buy property near the bar or restaurant (Moseley Village for example) because it's a lively, cool place to live - but they never actually drink there?

It works the same for museums and theatres as well. How many people love the fact that Birmingham has such a great cultural offering, but never taste it themselves?

Whether you visit them or not, conferences and other big events are important in getting cities noticed. A few weeks ago I wrote about bumping into some foreign delegates and the impression of Birmingham they would be taking home with them.

Whenever it has hosted a big conference or a world championship sporting event Birmingham has all too often fallen into the trap of trying to quantify its success on the international stage. It is declared a success simply because so many thousands of people visited or took part. Quantity, not quality, has been given precedence in the promotional argument that biggest is generally best.

The idea of taking delegate numbers, multiplying by the average cost of a hotel room and adding the bar bill is about as useful as calculating 'equivalent advertising value' in the PR industry. It makes interesting reading, it tells us something - but it is not the whole picture.

That's why a party conference is important: because it brings important people to Birmingham.

We often say that the city suffers from outdated perceptions and that once people visit they change their view. I certainly experienced a lot of that among journalists and others visiting during the European Capital of Culture bid.

Sometimes it is important to communicate the scale of an event, but let's not get too hung up on figures.

We can have thousands of Rotarians drinking in our bars, a group of politicians who (one day) might decide the country's future or one solitary visitor who comes quietly, unannounced, goes to a concert at Symphony Hall, then gets out his cheque book to relocate a multi-million pound business here. We should welcome them all.