A friend of mine recently flew ZRH-DUB on EI. He only had one checked luggage (about 20 kg, not exceeding the maximum weight) and a small carry-on with him. Nontheless, at check-in in ZRH, he had to pay 12 CHF (about $9) for the bags. The receipt he was issued by Swissport says "XBAG: 1 bag".
I have never heard of such a thing as having to pay for carriage/handling of the first bag. Shouldn't this be included in the ticket price?