Arts internships: chance of a lifetime or cut-price labour?

guardian.co.uk: "A young acquaintance of mine recently got her first paid job in theatre. She left university two and a half years ago and, since then, has worked part-time in a bar, while also undertaking a series of unpaid or expenses-only work experience placements and internships. Six, to be exact. Now approaching her mid-twenties, she has just got her first salaried employment in the arts. She counts herself lucky, even though it is only a part-time job. She knows people who have been working unpaid in theatres and companies even longer."