Sorry, but that's pretty bad research for your new ereader if you don't know that you need to login to the device. As to ads, there aren't really any. There will be some tiles for the store when you first start it. If you buy books from Kobo and sync them, there can be other suggestions as you go along, but they can easily be removed. And if you never sync to the Kobo server, you will not see them.
As to the login, a dummy email address is fine. Kobo doesn't check it. It just needs to look like an email address. Or a few moment searching here will find how to skip the login process.
|