It's been a year since Amazon bought Whole Foods in a $13.7 billion deal that sent tremors through the grocery industry.

But while Amazon – and Apple - are major disruptors to business and marketing, it's the smaller companies which will shake things up now, according to Wenda Harris Millard, vice chair of advisory firm MediaLink.

"I think the real disruptors in many, many ways are … the Dollar Shave Clubs of the world, the Kind Bars, the Red Bulls," Harris Millard told CNBC at the Cannes Lions International Festival of Creativity in France this week.

"Those to me are shaking the (marketing) industry to the core. In addition to some of those big, big players, but … they are to be contended with." Unilever bought razor subscription business Dollar Shave Club in a $1 billion deal in 2016, while Mars bought a stake in nut bar Kind in November.