The planned €3.1bn (£2.1bn) merger between Adidas-Salomon and Reebok is all about catching up with Nike, especially in the US.
The US accounts for 50% of the sports footwear market. Nike has the lion's share, taking 36% of the $8.9bn (£5bn) US sports shoe market last year.
By contrast, Adidas's share was only 8.9%, while Reebok controlled 12%. But together, Adidas - based in Herzogenaurach, Germany - and Reebok, based in Canton, Massachusetts, could give Nike a run for its money.
That is what investors seemed to think , with both Reebok and Adidas shares making strong gains following news of the merger.
However, not everybody was convinced about the merits of the deal.
"I would watch the execution of the integration very carefully because it won't be easy to integrate the businesses - Adidas's focus is on sport but Reebok's is on lifestyle," Volker Riehm, a fund manager at Activest, told Reuters.
"Apart from that, Adidas is creating a load of work for itself when the World Cup is just around the corner."
Adidas is a major sponsor of the World Cup, which is taking place in Germany next year.
But if the two companies manage to integrate properly - a big, because mergers are hard to pull off successfully - the combined firm could pose a serious challenge to Nike.
Adidas has always made good products, but has failed to match Nike's marketing prowess. But things could have been different had Adidas, rather than Nike, signed up the basketball legend Michael Jordan.
In 1984, Adidas had the chance to bag Jordan - then a promising National Basketball Association rookie. But Adidas, who in the past had signed basketball stars such as Kareem Abdul-Jabbar and the boxing legend Muhammad Ali, decided to give Jordan a miss.
Adidas's loss was Nike's gain. Nike offered Jordan a $2.5m contract, launched launch a $65 basketball shoe called the Air Jordan the following year and went on to become one of the world's most well-known companies, complete with swoosh logo and "just do it" motto.
Adidas will be relying heavily on Reebok's marketing nous to take on Nike in the US.
Once associated primarily with the aerobics boom of the 80s, Reebok has made inroads with the youth market by signing up the likes of the rapper 50 Cent. However, it had to drop ads featuring him in March amid complaints they glorified gun violence.
For its part, Adidas recently teamed up with the fashion designers Stella McCartney and Yohji Yamamoto on a line of trendy training kit sold through fashion boutiques.
Herbert Hainer, the chief executive of Adidas, described the merger as a "major strategic milestone" and "a once in a lifetime opportunity". He will be keeping his fingers crossed that Adidas-Reebok will not turn into a repeat of that calamitous German-US merger, DaimlerChrysler.
