This is an exciting topic to reveal! A lot of Amazon sellers using Lightning Deals to boost sales in a short period with a steep discount (usually 50% or even more).
Here are a few significant tweaks you need to do so to launch LD more efficiently:
First, make sure you do it for your future organic sales growth, not for a quick profit.
Second, make sure you have four types of targeting inside your auto campaigns (Complements/Substitutes/Close match/Loose match). If you have old auto campaigns, there are no targeting options, so create the new auto campaign to open access to this feature.
Third, if you were running LD's in the past, make sure you analyze the "Complements" targeting:
If the ACOS on Complements was similar to other targeting types, make sure you lower your bid for the next Lightning Deal;
If the ACOS on Complements was lower than other target groups, you already found the sweet spot. Please don't touch it. You are a winner!
If your past LD's didn't work out, increase the bid on Complements by 50-100%
If you just launched your Auto Campaigns make sure the Close Match and Lose Match are getting traffic and then increase the bid on Complements by 30-50%
IMPORTANT!!!
Do not use high bid for Substitutes that will kill all the traffic from Lightning Deal.
Make sure you increase your budget in 3-4 times, especially if you already found your sweet spot.