It is always useful to provide links to your books on various different retail sites. And linking to your books on Kobo via your website, your blog, on Twitter, etc. helps your fans who prefer Kobo to easily find and purchase it.
With that in mind, please note the following:
The best way to link to your eBook on Kobo is to use the following formula:
(replace “eISBN” with the 13 digit ISBN of your eBook)
You might notice that, if you enter this exact URL into your web browser, it will automatically redirect to a much longer less human-readable URL. This is because Kobo is automatically redirecting to the most recent version of the ePub file you have loaded. If you link directly to the long URL and then you update your ePub file (ie, the content of the eBook itself), a fresh new URL will be generated and the old URL will be deactivated.
This ensures that customers can’t purchase the old version of your text (however, Kobo needs to ensure that customers who already have the old version in their libraries still have access to that version — yes, they can refresh and update from the old to the new, but we can’t do that automatically for them because it would negatively affect their bookmarks and any other annotations, notes, etc they might have added to the originally purchased version)