But while as the Zenith International reported showed, if growth has slowed, it has far from dried up, with some of the leading soft drink companies trying to get in on the act and others looking for new audiences for their existing brands.
Mintel's Global New Products Database reflects this changing nature of the European marketplace, and shows that while many brands seeking to copy runaway market leader Red Bull have already disappeared from the market, there are plenty of others waiting to take their place.
Many of these 'me too' brands follow not only the packaging look and product content pattern of Red Bull, but they also choose names which are remarkably similar as well.
Take Mad Bat for example, launched in Germany back in October, or Blue Monster launched in Spain a month earlier, or even Dark Dog, one of the more successful Red Bull 'wanabees' which was launched in Greece last year after successful launches in Spain and France. All are taurine- and caffeine-based, like Red Bull, and come in the same slimline 250 ml can favoured by the market leader.
Red Bull has always refused to associate itself officially with the way in which the brand appears to be most popularly consumed - as a mixer with vodka or other spirits - although its marketing, along with that of many copycat brands, is frequently targeted at consumers most likely to drink it in this way - 18- to 25-year-olds.
Little wonder, then, that Coca-Cola, whose own can designs have been copied by a multitude of cola makers the world over, adopted the Red Bull-style can for its energy drink Burn, launched in numerous markets over the last year and most recently in Portugal in October, according to the GNPD.
Coca-Cola's core audience for its carbonates is not necessarily of legal drinking age, while the Burn brand, although again not openly marketed as a mixer with alcohol, targets clubbers, students and what it calls 'easygoers', all of whom are much more likely to choose an energy drink that looks like Red Bull than one that looks like Coke.
Other products which have a very different positioning also often seem to follow the standard Red Bull design. EJ-10, for example, launched in Germany and Ireland last year according to the GNPD, is branded with the colours of the Jordan Formula One racing team, and is targeted primarily at drivers needing a burst of energy to keep them alert at the wheel.
But it too has adopted the slimline can design more associated with Red Bull - potentially running the risk of also being seen as a mixer, not a good image for a product designed for drivers.
Another brand with more lofty pretensions is the Wellman brand from Vitabotics, launched in the UK in September, which is marketed more as nutritional energy drink for men than as a mixer product. Backed by a £750,000 advertising campaign aimed at differentiating it from the crowd, the brand has nonetheless opted for the same slimline can design as Red Bull, rather than, say, a PET bottle which might have better matched its health, rather than simply energy, positioning.
Brand marketers are clearly very aware of the impact of packaging on consumer purchasing decisions, as Zenith's report suggests. A bottle or can which stands out from the crowd can be a good thing, offering drinkers something out of the ordinary, but consumers also expect certain products to be packaged in certain ways, even in these days of multi-format packs, and bucking the trend can be a gamble.
Bomba, the Austrian energy drink brand, is a good example of this. According to the GNPD, the company launched its core brand in France back in October, offering something different in the form of its 250 ml glass bottle in the (sometimes controversial) shape of a hand grenade.
This design has been part of the success of Bomba, marking it out as different from Red Bull and its cronies, but the company is now also diversifying into other designs as it extends and refines its product range.
One example is the Solution E drinks range from Bomba, a product aimed more at the sports end of the market and containing the decidedly unappetising sounding ingredients brine and colostrums. Launched in Germany in October, the brand comes in a more sophisticated bottle design, reflecting iis different positioning.
But perhaps not surprisingly, Bomba's latest packaging format is… the 250 ml slimline can! The company has just launched its Yellow Classic energy drink brand in this format on the German market, perhaps out of a desire to see if its success can be matched by tackling Red Bull head on.
But some energy drinks are entering the market with a truly different design - one of the factors which Zenith claims will maintain the solid growth rates in the years to come - in part due to their different backgrounds.
Launched in Italy in November, Energade Explosion is a taurine-based energy drink which breaks the mould of slimline cans, coming in a 250ml plastic bottle. The reason? It was created by San Benedetto, a mineral water company with a great deal of expertise in PET bottles.
The 'energy water' was originally available in a 500ml format, a throwback to its mineral water origins, but has now been launched in the 250ml format which appears to be the industry-wide standard for energy drinks.
Despite being billed as an energy drink, Energade is more akin to sports drinks such as Lucozade, Powerade and Gatorade, another factor reflected in its choice of PET, but it has bucked the trend of recent months by offering a smaller rather a larger format bottle. Other new launches such as Energise from Ireland's Cantrell & Cochrane and Rehydration Aquarius from Coca-Cola in the Netherlands have seen the launch of 500ml variants, ideal for the thirsty sportsman and more likely to wet his or her whistle - and replenish bodily fluids - than a 250ml shot.
Another brand which reflects the origins of its parent is Battery, highlighted by Zenith as the only brand to outsell Red Bull, at least in its home market of Finland. Owned by the brewer Carlsberg, Battery comes in a 330ml can - more usually associated with beer - and this has clearly helped it stand out from the Red Bull-led pack.
It has just been launched in this format in Turkey, while Carlsberg has also decided to roll it out in Switzerland in a 250 ml, but with the same squat design rather than the now-traditional tall, slim can.
But most striking of all is Energy Gel from Maxim, launched in the UK in July, which although it clearly targets drinks brands is in fact a gel, as the name would suggest. Packaged in a 100g flexible pouch, Maxim is being marketed as an alternative to the raft of energy drinks, though whether its proposition of boost without refreshment will prove a winner remains to be seen.
In any case, it is innovative products such as this, coupled with new packaging designs and formats designed to make consumers think about which brand to choose, which are keeping the energy drink market alive. But it is likely to be many years before we see the last of the Red Bull clones launched.