2015 has seen many interesting developments in everything that concerns 
1. Mobile Optimization Will Overtake Desktop Optimization
Mobile search has been growing in importance for the last few years, rising from an insignificant addition to the prevalent desktop search to being equal to it in scale. In 2015 we finally saw what was aptly called Mobilegeddon – Google finally acknowledged the overarching importance of mobile search by releasing the corresponding update and declared that mobile traffic graded up to desktop traffic. This trend is certainly going to continue – it is more than likely that in a few years, desktop and mobile traffic will swap places, with desktop serving as a humble supplement this time; and you will need a SEO service that understands this and already moves in this direction.
2. Growth of Interactive Content
Most SEOs concentrated their attention on content for the last few years under the persistent pressure from Google, but it is interactive content that is likely to become the next big thing in 2016. In 2015 we saw the rapid rise in the use of infographics, but they are mostly popular among SEOs and not the end user. Interactive content, on the other hand, encourages, well, interaction and promotes a more active position on the side of the user.
3. Increased Importance of Video Content
Although text is still considered standard, during the last few years we’ve seen a gradual shift towards other, more visual types of content, namely video, infographics, images and animation. The ongoing experiments in this field will lead to the changes in perspective among users as well – they will grow to expect video and other kinds of visual content, which can be seen even in Google that relatively recently introduced video ads in search results. Soon video is going to become just as important, if not more important than text – probably as soon as 2016.
4. Voice Search Rising
Next time you use Siri, Cortana or Google Now, think about how you do it and what implications it carries for the search industry. Queries processed through digital assistants are usually much different from the ones that are typed in, and with their growing expansion we are going to see a whole new subgroup of keyword queries, most importantly the ones imitating oral speech.
5. Local Search Is Going to Explode
Local search was expected to be the leading trend in 2015, but it didn’t manage to acquire the necessary momentum. With the release of wearable devices like Apple Watch, however, local search indexes are going to be more important than ever.
Of course, SEO is a rapidly developing and rather unpredictable business, which means that none of these trends are set in stone; however, the overarching tendencies speak strongly in their favor.