If found guilty, it would be second time a European regulator has taken action against Google.
Internet's dominant company is not growing traffic volumes to make up for downward ad prices.
Social giant believes landmark US Federal Trade Commission fine over privacy breaches could be as much as $5bn.
P&G brand chief wants to prioritise transparency and control.
Tech giant has dialled back 'ridiculous' promotion of private-label products.
All Nestlé brands in the US have paused advertising on YouTube.
Google 'did not properly obtain consent' from users
Apple's share price dropped by 7% in after-hours trading.
Mistake reported to have cost Google $10m.
Brands operating in less mature programmatic media markets need to establish direct relationships with publishers, global study warns.