Visa Europe says the adoption of NFC contactless payments has reached a ‘critical point’ across Europe.

More than 19 million transactions took place in March 2013, driving the total spend on contactless cards and smartphones equipped with a Visa payWave app to over €1 billion (£856 million).

We start this week's podcast by talking about Yahoo and Tumblr before moving on to discuss Google's recent developer conference.

There are product announcements from BlackBerry, HP and the former MeeGo developers at Jolla... and there's some interesting mobile app news as well.

Yahoo! has agreed a deal to acquire blogging and media sharing platform Tumblr for approximately $1.1 billion (£724 million).

Tumblr will continue to operate as a separate business with David Karp as CEO.

Mark Bridge writes:

Last year, the Google I/O developer conference gave us plenty of product announcements: Google Glass, the Nexus 7 tablet, the Nexus Q device and the Jelly Bean version of Android. This year’s announcements were less dramatic: a streaming music service, a Google-friendlier Galaxy S4 and some game development tools. Coincidentally (or perhaps not) Apple announced its 50 billionth app download in the middle of the event.

Juniper Research has forecast that 2 billion mobile and tablet users will be watching TV and video on their devices by 2017.

This worldwide growth is being attributed to two main factors: the uptake of higher-quality mobile devices and the growing popularity of short (and easily shared) video clips.