Read Google uses Gmail to track a history of things you buy — and it's hard to delete by Todd Haselton,Megan GrahamTodd Haselton,Megan Graham (CNBC)
Google collects the purchases you've made, including from other stores and sites such as Amazon, and saves them on a page called Purchases.

Apparently is a reasonable place one could start for creating acquisition posts on their website. The downside is the realization that Google is tracking all of this without making it more obvious.