When Download last surveyed the adtech landscape 12 months ago, new regulation was the focus, with rules being considered for areas such as native advertising.

A year on, sponsored content is everywhere and there is a reasonable case to be made that consumers are sufficiently used to it that they understand who has written it and for what purpose. So what are the new regulatory and other challenges for those involved in adtech?

As Mark Greenbaum discusses in this month's edition, the number of adtech providers and intermediaries has grown enormously. Consumer access is also increasing or at least shifting - among mind-boggling statistics, the IAB reports that digital ad spend in the UK alone in H1 2015 was nearly GBP4 billion, up over 13% in a year. This might suggest we are in an expanding market, but the audience and its available time remains roughly constant, budgets continue to shrink and price pressure is intense. Some governments are finding ways to squeeze the business still further, as Orsolya Banki discusses in respect of Hungary where new higher rates of tax are being applied to digital marketing.

Inevitably, more consolidation of providers is underway and the divide between media owners and intermediaries/agencies continues to blur, with media owners and long established agencies bringing more adtech capability and technology in-house. Rules on transparency over exactly who an agency is acting for, such as the extension of France's Loi Sapin to digital,discussed by Diane Carpentier, are going to become of greater importance though questions about how such requirements apply to programmatic buying remain.

With consumers becoming ever more savvy about the digital environment and with a new generation of digital consumers emerging, the challenge of how to put a good advertisement in a suitable place for the right audience member remains. Marketing and content delivery has become ever more data driven as a result, whether in search, social or display. The European Court's decision on Safe Harbor transfers of data from the EU to the US may cause significant problems for digital services unless the promised solution can be found within a short timeframe.Lucy Lyons discusses the issue of data exports and the current position.

Another headache for advertisers is adblocker software, which presents a challenge in reaching the audience at all. Different parts of the digital ecosystem have differing views on the pros and cons of adblocking and its legalities are the subject of debate in several countries (see, for example, the discussion of the position in Germany by Steffen Kämper and Dirk Wieddekind), but it's a debate which still has some way to run.

Regulators' concerns that consumers should be able to trust what they are reading, seeing or hearing have not gone away, but have evolved as the media evolves. With user generated content in the form of reviews forming an increasingly important part of purchase decisions, the UK Government has recently completed a consultation exercise around online reviews and how to ensure these can be trusted not to have been posted by a biased party, whether on behalf of the vendor itself or a competitor. Fake reviews, and indeed fake users, are one aspect of a constant arms race which platforms and advertisers are on the same side of, and a continuing struggle to ensure both that digital advertising is trusted and effective and that advertising revenues are not stolen. We wait to see if national governments, and the EU's digital single market initiative, can help in providing tools to assist in deterring such practices while maintaining light touch regulation of a rapidly moving sector.