Offers often work better when they come with some sort of urgency, prompting members to take the offer now rather than defer to later (and forget about it).
It would be helpful if offers came with the option to define:
a) a maximum number of redemptions
b) an end date
…with a representation in the frontend so that people who look at the offer see the limitation.
Fwiw, both of them can be used already with a bit of flintstoning: You create the offer, communicate a limitation directly in the email/post and manually archive the offer once the limitation is reached.