Why publish instead of attaching
A PDF attachment is heavy, it can be blocked by mail filters, it opens differently on every device, and it tells you nothing after it leaves your outbox. A published flipbook is a link: light to send, readable on a phone, correctable after the fact, and measurable page by page.
It also stays yours. The publication carries your logo and colours, sits on a page you control, and can be embedded inside your own website rather than living in someone's downloads folder.