Kobo has a free ebook page here at Top Free eBooks.
This page contains in-copyright free ebooks, as opposed to public domain classics. The “free ebook” link at the top of the Kobo page just points you to public domain stuff. You need to go to their Top 50 Ebooks page and then to the Top Free eBooks page to get current stuff. Not very intuitive.
Today’s top free ebook is The Penguin Holiday eSampler.
The Kobo site doesn’t seem to have a deal of the day, or at least I can’t find it. When I go to their Great Reads under $4.99 page I get the encouraging text: The list “Great Reads Under $4.99” is empty or you may be geographically restricted from viewing its contents – try selecting a new list.
The $4.99 list disappears for a day or so from time to time. The big story for Kobo is their discount codes for non-agency books. (and the regional variations for those codes that often result in a single use discount code being able to be used multiple times).
There is also an old trick. You can search 0.00 at any online ebook selling site and you will get a bunch of results pointing to the free ebook.