The merger between European retailers Ahold and Delhaize is significant because it will allow the group's to scale up in the key US market, where the majority of revenue is generated. Announcing the deal, the companies said EUR500m (US$560m) in annual synergies are on the table. But these, as and of themselves, will do little to raise the combined group's lacklustre US growth trajectory. Katy Askew looks at the impact the merger will have in the US - and whether Ahold Delhaize will deliver on their promise to drive consumer-led innovation.