How would you double active users on Facebook Shop weekly when only 6% of FB users remain active in the first week and 0.4% remain active after 3 weeks?

Here's how I'd approach this Facebook PM product improvement question:

Context

Facebooks mission is to connect the world and provide the tool to build the community.

Let's understand what is FB shop first - its a community marketplace and lets you buy thing new/used from people around you 

Sellers and shopper connect offline to figure out the logistics 

Clarity

How would you double weekly active users on Facebook Shop when only 6% of users on FB remain active in the first week and 0.4% remain active after 3 weeks.

When you say FB shop are you referring to FB marketplace - yes 

When you say first week I'm assuming you're referring to the week after they become active on FB shop for the first time i.e W0 is when the user dsicovers FB shop - Yes

When you say active are referring to app opens for FB shop - yes

We want to double weekly actives but customer retention is poor so we want to solve for that i.e customer retention

Users

Who uses FB marketplaces - Young adults/teens, single working individuals, flatmates/married couples under 45 and 45+ cohort

WRT shopping the purchasing power lies with Single working individuals , flatmates/married couples under 45 and 45+ cohort however 45+ cohort doesn't have good adoption when it comes actually buying online so I want to discount them as well.

I want to focus on the cohort from 25 to 45 since they form a significant chunk of FB's users and also purchase online frequently

Needs/pain points

- they frequently buy groceries/perishables from a local grocer but it takes a lot of time to deliver and often has minimum order value

- I often orderout food since I dont feel like cooking at home 

- not the most competitive prices since the grocer has monopoly

-I often go to branded showrooms for my large value purchases like high end earphones since I don't trust local sellers

-I want the convenience of a drop to home 

Gaps identified

the current categories that FB marketplace offers are categories where the purchases are made typically once a year - earphones, mobiles, etc

Vector chosen

I want to make FB marketplace more relevant on a day to day basis

Tactics

• Onboard local sellers for food/perishable and users can order groceries online: I feel that onboarding these categories will make Facebook relevant for more weekly purchases and drive active. 
  Allow for catelogue on these seller pages, in addition sellers can also set up their own offers to have more traffic + fresness is an extremely important criteria for purchase so sellers can mention when they got the fruits etc 
  High reach high impact high confidence medium effort - PICK ( Why medium effort? - I am a tech company so I dont want to invest in ops, I'll mostly partener with a dunzo or swiggy stores to help drive this)
• Shopping List building via FB: Users can set up a group that buys groceries and users can keep adding it to a shopping list so that whenever the user opens FB marketplace I can show relevant grocery sellers to the user, this leverages Facebook's network and aligns with it's mission + is a differentiator
  Medium reach(since not everyone lives in a shared apartment), medium impact, medium confidence, medium effort - PICK
• Early morning low touch delivery:  Early morning low touch delivery is a fantastic way of locking in users/driving repeat usage behavior while ensuring conveneince. We can tie with partner to enable early morning low touch delivery ( users build a cart and pay for it and it gets delivered to them early morning everyday)
  Medium reach, high impact, high confidence, high effort - PICK 
• Meats: Meats are not bought as frequently as greens and has its own factors ( which cuts how was the live stock raised) but it's a high traction category
  Medium reach, medium impact, high confidence, high effort - Pick post MVP , once the product has traction