Is Google showing us online ads are not effective?

Astonishing: In order to promote their Chrome browser in the UK, Google uses billboards and free newspapers.

Not just one small billboard, but many in medium to big sizes.

Not just a small advert in the free Metro newspaper for commuters of public transport in the UK (1.3mio people or more), but on the front and the back.

If on-line ads would be effective, we would have all seen on-line Chrome ads.
Have you seen any on-line ads for Chrome?

If Google uses mainly off-line advertising for promoting their products, giving the doubt of the effectiveness of on-line advertising, then why shouldn’t you start doubting about your on-line marketing campaign?

Any doubt about your on-line advertising? Apparently Google has.