I saw this yesterday in a shop window and loved it. It's an ad for a proposal for marriage for any illegal immigrant (woman) with an email address, and a promise that it's "economical". The actual text reads:
"Foreign Woman and need papers? I'll marry you. Economical. Write to me and we'll talk." Followed by an email address (which I've blurred out intentionally).
Now, I know that this is a quick way for illegal immigrants to "become legal" and there are work contracts that go on for sale in South America for around 3000 Euros (I know a fair few people who have paid that), and I'm not making a joke about the situation of immigrants at all. What I loved about the ad, is that these kind of things that I've mentioned usually are done "behind closed doors" or "I know someone who might be able to help you out..." - this ad is in a fairly big shop in the middle of Barcelona's Old Town brazenly displayed in the shop window for everyone and anyone to see. Classic.
Coming to Barcelona soon? Consider apartments for rent in Barcelona instead of a hotel room, and for a heads up on the city and its neighbourhoods, see this Barcelona Guide.