Proving your case
To convince your reader that you have formed a sound argument, you need to finalise your introduction with a concluding sentence.
The concluding sentence needs to show the significance of the evidence in making your case, for example:
... The large numbers of children and adults attending the functions, and the high sales figures for named products, coincided with the period when record numbers of books were sold, clearly suggesting that the global success can be linked to careful marketing.