Well, I don't really think it's "luck"; it's the fourth straight year of attendance increases; average attendance has increased 15% since 2001. Only Ottawa has shown a drop in attendance over this time last year.
The Ticats have probably the best sales team in the CFL. I believe they are more than capable of selling tickets regardless of the team's record.
If this year's performance affects Hamilton's attendance, it will only be marginally. (I know it's not stopping me from renewing my tickets.) The season ticket base, while solid, is about 15,000; only about 5,000 higher than their worst seasons attendance-wise. That means they still sell 12-13,000 tickets per game outside of that. If they're doing that with a 2-10 team, imagine what they'll do next year when the team is bound to be better.
If they lose any, it'll be from those 5,000 new season-ticket holders. Even if they lose half of those, they're still looking at an average of about 26,000. And if the team is better, they'll probably more than make up for that with increased sales of individual game tickets.