Shifting gear from good samaritans to restitution claimants who conferred a benefit in the pursuit of their own self-interest raises a theoretical puzzle. On the face of it, these claimants – think, for example, of a class action member who pays her lawyer's fee, a mortgagee who pays its mortgagor's taxes in order to prevent foreclosure, or one of several tortfeasors who settles with the victim – can raise none of the reasons for restitution used in either chapter 3 or chapter 4. Their will has not been vitiated; on the contrary, they typically act with some deliberation and intent. They are not (necessarily) do-gooders: in fact, as the title of this chapter indicates, their claim is characterized as deriving from actions that are aimed at being self-serving. And while they can generally show that they have conferred a benefit on the defendant, the defendant can typically invoke the strongest defense – according to both law and theory – of restitution defendants in the good samaritan setting: in some cases she actively indicated her unwillingness to pay for the benefit; in many others, she could at least have been asked (no emergency made communication impracticable). Why should such restitution claimants ever be allowed – even encouraged – to “officiously meddle” (as the common epithet goes) in the defendant's affairs? And why is it that such self-interested claimants actually fare relatively well in the common law of restitution (at least as compared to their other-regarding counterparts)?