I looked at the amazon page for my own book, and got the following email:

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Based on your recent visit, we thought you might be interested in these items.

Linux Application Development
Michael K. Johnson, Erik W. Troan
https://www.amazon.com/gp/product/0201308215/ref=pe_375520_379591630_em_1p_0_ti
List Price: $47.95
Price: $43.80
You Save: $4.15(9%)