Well since you've sold out your past 2 games, I'd have to say that the fans are rewarding you for winning by showing up. My advice: don't worry much about merchandising, it makes a very small difference unless you have a NT player. I have one of the best teams in my league and am below average in merchandising but I make up for it with much larger ticket sales than most (if not all) of my league mates.
As an unrelated aside, you need to make sure to keep your game shape in line. Try not to play your key player more than 65 minutes in any given week... 55-65 is the best. This will improve their game shape and that's the single most important stat to determine whether you play well or poorly.