Modern Memories - Does my website explain my product? Thanks in Advance!

Wow! Very cool product, and not what I was expecting at first! So... Everything makes sense to me, and flows really well, until we get to the Kits list. I wasn’t expecting to select from a themed kit, and just thought that I was going to get a selection of generic letters to send out. This project might be suited for a platform that is more customizable than Shopify. I feel like a responsive, multi-step form that allows a user to select who the letter is from (mother, father, wife, grandfather, etc), and who the letter is to (son, granddaughter, nephew), then you can create a “customized” package for every person who comes through your store. You could also allow them to select the increments that they would like the letters sent at, and could have adaptive pricing based on all of these factors. You have some great opportunities here! I am looking forward to seeing how this continues to grow.

I immediately understood what it's about just from the tagline, before even opening the site. Good job with the copy. The explanation on the website itself does a good job of further explaining. Only catch: Your audience might be older & less savvy than the IH crowd so try testing it with unbiased older folks.
I also agree with @collinlee about having more options but I guess you can add those as you go?
About growth: I see sharing as a particularly tricky task for less proficient users. My grandma would love the idea but might not copy/past the link properly and her friend might not be able to figure out how to correct the error/search for it. How can you build viral loops that are super easy?