Does a player's wishlist mature like a fine wine over time and convert into a sale... Or start to stink like old cheese after a few months?
Here is some pioneering research on Wishlist Quality By Age using data from Ancient Enemy. In summary, it's a pretty bumpy ride. But we'll go into the details a little more below.
Month 1 was when we made the page live, and when lots of our true fans signed up. Month 16 is the month before launch, when we were talking about the game a lot on social media and the topic was fresh. Month 17 is launch.
Note that launch month is down in terms of conversion %, because LOADS of people add your game to their wishlist after launch because they don't intend to buy it until it goes on sale.
This data doesn't include wishlist deletions. We cannot track when those which were later deleted were originally added. (Valve probably has this data). So it's possible deletions would tweak the data to a small extent.
One conclusion is that the first batch of wishlists convert well (fans probably), the middle batch is OK, and wishlists added just before launch are still hyped at launch. Post launch wishlists are poor quality, which many developers knew anyway.
We would love it if other devs posted their data. But note it's a bit of a pain to find out. You'll need two separate csvs from the Steam wishlist backend, then you'll have to summarise by month and work out the % conversion.
Other games may not see the initial spike as we suspect that was probably our existing fans. YMMV. But it may also have just been people who saw it and went "hell yeah, that's for me," more than some luke warm customers later on.
As always, thanks to our patrons for supporting us. If you appreciate this type of data then please do consider becoming a patron!