Last year I had 7 interviews (but I really only count 6 because one site interviewed over 120 people and their interview day was so disorganized that many applicants did not even get interviewed by as many supervisors as were supposed to) and I did not match. I know a student who only had 1 interview last year and matched (his site actually ended up in phase II, so unless they did not rank him at all, he was pretty much going to match. None of my sites, on the other hand, ended up in phase II). My program also makes us do APA internships and only a little over 60% of people matched to APA sites last year. This year, I already have 9 interviews scheduled and am waiting to hear from a bunch more sites. I would be happy if I had around 13, but still there is no guarantee of matching, especially at an APA site.