The things that made me get the Kobo Touch:
* Among the lowest-priced ereaders at the time (July 2011), yet not sacrificing on a competitive feature set
* Kobo employees having a noticeable, active presence on MobileRead
* works reasonably well with Linux
* Canadian company (me being Canadian)
* wide range of formats supported
* ability to upload free ebooks found around the Internet
* ability to read library books
* fairly recent model, so it won't be obsolete as soon (as opposed to getting an old model just to save money)
and now that I actually have it, I can report that I'm very satisfied with it.
The other ereaders I considered were Sony (too expensive for newer models), and Kindle (very close contender, but I picked Kobo because it was Canadian).