According to reports out of Italy, Napoli have sold only 9000 tickets to today's match at the Stadio San Paolo against Palermo. Assuming that's in addition to this year's season ticket sales, that will put the crowd at under 17,000 people.
The fanbase is obviously very discontent with the season so far, and they're showing it with their wallets. They put together a good crowd for the home opener against Chievo, but that loss now coupled with the Champions League faceplant and the loss to Udinese has killed what little good will was left as far as buying match tickets goes.
This will be the second straight poorly-attended match at the San Paolo, after Sparta Prague drew maybe 10,000 people to the stadium. At first people blamed the late start time and the fact that it was a mere Europa League match for the small crowd, but now that it's happened in the league it looks more symptomatic of a wider problem.
You could argue that "it's just Palermo," but the last time they were in town the match drew over 30,000 fans, and that was when the rosanero were on their way to relegation. Besides, this is a good team with some exciting talent, fans generally come out for those more than they do the likes of Chievo.
This is a concerning trend that's starting to form. Ticket sales are a huge part of any club's revenue stream, and this fan discontent is hurting Napoli in more ways than just having a quiet stadium. Hopefully the team turns around their performances soon and the seats fill up before things go too far sideways.