Mercedes motorsport boss Toto Wolff believes that Formula 1 may have to ask tough questions of itself if the German Grand Prix does not attract a big crowd.
With German television audiences already in decline, ticket sales for this weekend's race at Hockenheim are not pointing towards a sell-out even though German Nico Rosberg is leading the championship for Mercedes.
Wolff admitted the lack of crowds on Friday were disappointing, but he reckoned that a better gauge of the situation would come from how many people turned up on Saturday and Sunday.
"It's not satisfying," explained Wolff. "If you compare Hockenheim Friday to Friday at Silverstone and Friday in Austria, it's a different world.
"We have to understand why that is. I'm not sure whether we have an exact number for Sunday already - you know, there are lots of people probably deciding at short notice, depending on the weekend - and we have to analyse the phenomenon.
"If the weekend continues like it does now, we need to think about it."
F1 is facing growing calls to consider radical changes in a bid to stop interest in it declining - with FIA president Jean Todt this week backing the idea of a summit for the sport to address its issues.