We are all about perpetuating your data into the distant future.
So, first off, we NEVER delete any user-supplied data. Secondly, even if you let your subscription lapse, your account remains open and you can still view any data entered in your markers or snapshots including linked web resources. The only thing you will lose is your ability to view those markers, etc., within the map-tools themselves1.
The account-screen which displays your "stuff" (as it is affectionately called around here) is still a work in progress. Improvements in the near term will add any latitudes/longitudes associated with your data (for markers and snapshots in the First Landowner's Project), so you can have a permanent record of that information. We are also working on a way to at least describe your migrations in a narrative form.
Another feature that is in development is the ability for you to share your findings and created-data in publicly viewable web-pages for all to see. This is scheduled for release later this year, so please watch future newsletters for announcements.
This is probably a good place to mention that your data is being stored on services provided by the largest data vendor on the planet (as far as we know), Amazon Web Services. They serve tens of thousands of companies like us, including the most bandwidth-intensive account in the world, NetFlix.
Like anyone in the business of preserving data, we always recommend that you print out a hard copy of your work. Information in your 'Account' page can be printed, but the current format is not optimal---we are working on creating a more presentable format that will look nice in a binder or for sharing with others.
1. The only condition for the above is that you must keep a record of the email address and password associated with your account. Verifying you are who you say you are is MUCH more difficult if you forget your email and password months or years down the road, and the burden to do that necessarily falls on you.