The PostView is a new column written by senior execs working in the European online advertising industry.

News of the recent Peer 39 exit could well serve as a wakeup call to ad tech land. Some have become more realistic around the sustainability of over-invested companies, in a relatively small part of the industry. But others remain blinkered about the challenges of being a feature versus a business.

This is not to say that Peer 39 was or wasn’t aware of its own challenges; it's merely a fact that some have been over-indulging on the ad tech hype (including some industry publications, I might add).

A reason why there has been a lot of reaction to this exit in particular is because it has given many the opportunity to say, “I told you so”. Ever since the LumaScape beauty parade landed on vendor’s sales decks everywhere, many sage observers have put forward the argument that the industry doesn’t have enough of a market to sustain the vast numbers of intermediaries. And it may be starting to appear that they are right.

It is fair to suggest that major demand players, particularly from the agency side, want partners with significant scale. Significant product scale that is. Agencies are global businesses who often execute a global/local strategy with regards to its partners and operations. They ultimately want partners who can offer that all-singing, all-dancing "stack". It might not be the entire stack, like Google, but it certainly needs to be more than just a targeting feature. If that was the case, it would need to be approximating a mini-targeting stack - maybe dynamic creative solution with some real-time trading functionality.

The word ‘stack’ although overused to describe a business’ product road map, is becomingly an increasingly important strategy. It’s important from a revenue sustainability perspective and also from a general long term strategic play, helping answer that perennial industry problem: “how do we offer a counter-weight to the mighty Google solution”?

Businesses that were once just a feature company have started to assemble products (coupled with their own smaller M&A activity) to become "mini stacks". They have become acutely aware that one relatively cool nice-to-have feature is not going to sustain itself.

A good recent example of this was BlueKai who have become (by their own admission, admittedly) the “end to end data stack for the CMO”. It was initially a provider of 3rd party data. Is this a sign of things to come? Consolidation is no bad thing. It ultimately streamlines the buying process, reduces friction, makes it easier to spend money in digital and let’s not forget, also facilitates meaningful exits for the feature players.

An interesting recent development in relation to all this has been the launch of the AppNexus investment fund, AppNexus Accelerate. It would seem this initiative is all about feature plays. AppNexus appears to have launched this fund to help finance developers looking to build apps on and around the AppNexus eco-system. This further strengthens AppNexus’ own stack play - but also flies in the face of what has just happened to Peer 39.

There will inevitably be a swathe of investors nervously assessing the recent Peer 39 exit. There will likely be increased due diligence around those that do not seem to offer a sustainable business strategy. Some investment cash may even start flowing a little less freely.

The AppNexus Accelerate fund might seem out-of-step now. But the idea here is that ad tech feature solutions can be funded, built and distributed through the AppNexus stack without having to invest millions into companies like Peer39 - which were ultimately designed more as open and interoperable products.

It is certainly a savvy move from AppNexus, and possibly a more sustainable way for developers to roll out innovative ad tech features without going through the big funding process.

These observations could of course be completely wrong. Consolidation may indeed be a million miles away. The features business may be here to stay - and you could say Peer39 was just unlucky. Money is still being raised for feature companies afterall. Did anyone else notice that Moat, another intermediary with a vague business solution, just raised $12 million in a new round of funding.