Continuity programs give you stable and predictable income. This might help convince people to join.
Offer parts of what you provide in your continuity program (webinar, article, one-day forum access) for non-members for a one-time access fee. You should price the single access fee to make your monthly fee seem very attractive. So if your monthly fee is $79, you might want to offer a single access for a one-time webinar (that you would get for free weekly as a member) at $49.
More and more people outside the US want to invest in US financial markets.
A book, written specifically for non-US citizens living outside the US, covering all aspects of investing in the US financial markets. Chapters on existing financial markets, investment vehicles, how to open the needed accounts in the US, taxes, etc.
Help the parents deal with the decision of buying a book and also with questions that the child might ask or that the parents might want to raise as the child is reading through the book.
Publish a short guide for parents about the book. They can peruse it in the store to help them decide on buying the book and take it home for free with the book they bought to help them as their child reads it.
If your store caters to kids, make their shopping experience a delight, please their parents and have a chance to sell even more.
Offer a service to the parents where they order the kid’s present in advance. You gift wrap it for them and hide it somewhere in the store. You also write the kids name or otherwise mark their gift wrapped package with ink only visible in UV light. When they arrive, you give the child a magic wand (UV torch), and they go through the store searching for their hidden treasure.
Get feedback from one or more target audiences.
A service where you can “hire” people from your target audience for your new startup idea. You pitch your idea to them, and they give you feedback. The pitching will already make you rethink some aspects of your plan and your pitch, and the feedback will give you, even more, to think about.