Just discovered this site recently and was very impressed. If you already have a epub file, it's simpler than anything else to get it uploaded and on offer internationally. They are already known for global sales, this lets you in on their publishing scene as a self-publisher.
I'd put Kobo as #2 in your self-publishing sequence, only because they don't issue ISBN's. (Lulu.com is your first stop, just for that - plus Nook and iBookstore distribution - and Amazon's KDP is your 3rd stop. More on the publishing sequence strategy in a later story...
Here are a couple of promo pieces from Kobo on their Writing Life. The great part is that this gives more freedom to authors. In the first case, the author's agent told him to go ahead and self-publish to show that there was a demand for his books (which is seeming to become a more effective way of getting a publishing contract these days...)
This second video, while also company promo, points out that Kobo is international. So when you self-publish through them, your book goes into 128 English-speaking countries within hours, if not minutes. Very nice instant distribution.
And while I'm still getting caught up with my Kobo submissions (only 2 out of 14 done - rest today, I hope) - here's my latest releases page, which shows self-publishing can be done rather simply. It's a baby step from publishing on Lulu (as featured) to pumping them out as epub versions on Kobo.