Organic marketing, getting close to your demographic, has been part of the art of advertising for about as long as advertising has been a part of commerce. In modern times, when advertisements have to reach out to wide swaths of sweeping demographics in one fell swoop, it's hard to find examples of organic marketing in most mediums. Email, however, is a rare modern exception. In fact, it could be argued that email marketing is the utmost paragon of organic marketing, in some cases. Aspiring musicians and writers, small businesses and blogs write directly and personally to their fans, who normally tend to be a demographic of a very limited sweep; obviously, like-minded individuals will enjoy many of the same things, and most people will only sign up to get emails from a business if they enjoy the business and its products. Getting a customer to sign up for an email list is the gold standard of modern organic marketing feats. Organic advertising, however, can get lost in the sea of non-organic advertising, mostly sponsored, in a service like Gmail.
With the introduction of tabs and the ability to block senders as spammers, Gmail sealed email marketing's fate for its users, aside from emails that they enjoy receiving. Most advertisements and sponsored messages were squirreled away into the Promotions tab, where users rarely venture unless they know that they've categorized something in there that they want to see. By and large, it's a self-curated, user-driven feed. As of this writing, that feed is chronological, except for sponsored advertising. This means anybody that doesn't pay up to Google for a top spot risks their next customer casually scrolling on by in search of confirmation of whether they won a recently entered giveaway. This is in stark contrast to the format employed on social media, where users only see two types of advertisements; those they sign up for themselves by liking, adding or otherwise subscribing to the advertiser, and sponsored advertisements that paid to be in a user's feed. In both cases, the user is fed this advertising algorithmically. This means that users see ads that they're likely to resonate with. Gamers will see ads for games and gear, outdoorsy types will see advertisements for getaways and outdoor gear, and movie buffs will see advertisements for the newest movies. Would an approach like this benefit Gmail users and advertisers, or only one group of the two?
Consider for a moment the fact that Google retains immense amounts of user data, so much so that they're beginning to rival social networks in their ability to construct user identities despite the fact that many of their services see over a billion regular users. If Google can figure out what a person wants, why not show them ads that correspond to that? An algorithmic email advertising feed could be as simple as changing the order of the messages in the Sponsored tab, but it could also be a huge change that winds up being a breath of fresh air for both users and advertisers if Google plays their cards right with it.
One example of how it could work would be ads shown alongside normal emails. Perhaps this wouldn't apply to all messages, but almost every email in and out of a user's inbox has something to do with them personally, aside from meaningless spam. Google could pick up on this and show relevant ads. For example, let's look at an aspiring singer who happens to be a fan of Japanese RPG video games. This enthusiast records a cover of a song from Shin Megami Tensei: Persona 3 and sends it to a friend for evaluation before daring to post it on YouTube. If they drop the name of the game in their email, Google could show them an ad for the upcoming fifth title in the series, or other games by its developer, Atlus. Likewise, two friends planning a hiking trip could see ads for tents and hatchets in their exchanges.
An algorithmic feed could also be handled all wrong and drive users away, of course. The most obvious way to do this would be to pepper a user's normal inbox with sponsored messages based on their interests; while trying to get work done or hunt down important information they swear they remember receiving, a user would be bombarded with relevant ads cluttering up their inbox, which would be quite frustrating. A user may also end up seeing ads relevant to their general interests in otherwise irrelevant emails, if they don't contain much in the way of advertising keyword potential. For example, a long distance boyfriend and girlfriend are having a romantic exchange via email while one of them is out of the country and the mood is ruined by advertisements for local restaurants. Both approaches have their merits, fiscally, and a certain crowd who may approve of them, but in the end, it would be up to Google how to handle algorithmic advertising in Gmail or even if they want to do it at all.