#!/usr/bin/perl -w
use strict;

my %customers;

while (my $line = <DATA>) {
    while ($line =~ m/{(.*?)}/g) {
        my $customer_name = $1;
        $customers{ $customer_name }++;
    }
}

use Data::Dumper;
print Dumper \%customers;

__DATA__
AB1\tA{Daniel Wright}\sA{Jack Smith}\sB{Jane Goodwin}
QW1\tA{Samantha Patton}\sC{Timothy Eeckles}
AR2\tA{Jane Goodwin}