Put the ones to skip into a Hash not an array

my %skip;
$skip{$_}++ for qw(skip_me and_me and_this_too);

foreach my $line (@csv) {
    if ($csv->parse($line)) {
        my @fields = $csv->fields;
        $offer{retailer}=$fields[0];
        next if $skip{$offer{retailer}};
        $offer{productid}=$fields[1];
    }
}
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Cheers,
R.