There is provided an e-cigarette system including (a) a user-replaceable e-liquid reservoir for dispensing e-liquid and (b) a portable, personal e-cigarette device; in which the device includes or encases: an electrical or electronic fluid transfer pump, being configured to transfer e-liquid from the e-liquid reservoir to an atomizing unit in the e-cigarette device, the pump delivering e-liquid under pressure from the reservoir to an atomising unit positioned in the e-cigarette device; and in which the user-replaceable e-liquid reservoir is (i) inserted into, or otherwise attached to, the portable, personal e-cigarette device and (ii) engages with the electrical or electronic pump in the device and (iii) is not user-refillable. A user-replaceable e-liquid reservoir for dispensing e-liquid, and a related method, are further provided.