Design the entry for the list you want, not the count you want
Prize choice determines audience composition more than any targeting setting. A generic cash or gift-card prize attracts everyone, which means it attracts mostly people with no relationship to your category. A prize adjacent to your product attracts a narrower, more expensive-per-entry audience whose subsequent engagement is worth multiples more. If your goal is a list you will monetise for years, pick the adjacent prize and accept the lower headline number.
Keep the form short and put the marketing opt-in on its own line as an explicit affirmative action, separate from the entry itself. Consumers who tick it deliberately behave measurably better than those swept in by a pre-checked box, and the compliance position is far stronger.
Write the disclosure like it will be read back to you
State who will contact them, on which channels, about what, and how to stop. Name your company. If partners are involved, describe them specifically enough that a consumer would recognise the message when it arrives. Vague authorisation language is the root cause of most complaint spikes, because the consumer genuinely does not remember agreeing to what they received.
Retain the disclosure exactly as displayed, with a timestamp and source, for every entrant. If you later buy or sell data, that record is the difference between a transferable asset and a liability.
Survive the first thirty days
Sweepstakes traffic arrives in a spike, and spikes are exactly what mailbox providers treat as suspicious. Send a welcome message within minutes while recognition is highest, then warm up gradually rather than blasting the full list on day one. Segment by engagement from the very first send and stop mailing non-openers early — a smaller engaged list outperforms a large unengaged one at every stage of the funnel.
Validate addresses at capture: syntax, MX record, disposable-domain filtering and typo correction on common domains. Removing an invalid address before the first send costs nothing; discovering it through a bounce spike costs sender reputation you will spend months rebuilding.
Then give them a reason to stay
The entrant joined for a prize. The announcement of the winner is the natural end of that relationship unless you replaced the reason to stay before it arrived. Use the first weeks to deliver something with standalone value — genuinely useful content, a members-only offer, early access — so the list has a purpose after the draw.
Measure the programme on revenue per subscriber at ninety days, not on entries. Judged on entries, every sweepstakes looks like a success. Judged on ninety-day revenue, the adjacent-prize, explicit-opt-in, engagement-segmented version wins by a wide margin, and it is the only version worth repeating.