I could perhaps make 200 bought-for-myself ebooks my goal for next year. That should be ... doable, as I'm actually already finding it hard to find books to spend Kobo coupons on, and my wish lists are filling up at a slower rate than they used to.
In any case, I have now completed my primary challenge for 2013, which was 120 books read.
That does include ten Doctor Who anniversary series short stories, each bought and counted individually; on the other hand, I read one 600 page book twice (counted as one) and one 260 page book twice (counted as one), and on the higher end, there was Great North Road (1100 pages in hardback). So all in all, I think it evens out well enough.
I think my minor challenge for the rest of the year will be to make sure I've read everything I've bought this year (as far as ebooks go) that cost over $5. As far as I can tell, that's currently two books, one of them pre-ordered but not received yet, and one other. And I'd like to get done with at least 2-3 of the ARCs I've got but haven't managed to read yet.
Next year, I should try and tackle the ones bought in 2012, which cost over $5 each and which I still haven't read - that's going to be much harder as it looks like there are still 51 of those left (discounting the Harry Potters, which I've read several times on paper but not the ebooks). I'm not going to force myself to read those I don't currently feel like reading, but it's something to keep in mind whenever I have trouble choosing the next read.