hashtag, such as on Twitter

tag, label / tag (element of markup language)

event (social event) / (computing) event (action which triggers an event handler) / (video games) a scripted event, a cut scene

to use / to employ / to make use of, to apply / to spend

advertisement, publicity / propaganda

to advertise

please give me / (expressing a request) please do something for me

Please do (action)

Please do not (do)

please give me / (polite, imperative) please do something for me; expressing a request