Global digital ad spending is certainly picking up all around, but there’s an interesting little trend breaking out that shows that mobile could be seeing a bigger focus in the years ahead.

A report from eMarketer shows that, over the next year, advertisers will spend a whopping $64.3 billion on mobile advertising, a 60 percent increase over this year. However, that number’s going to get even bigger over the next few years, as it will reach $159 billion by 2018 — which accumulates to 63 percent of overall global digital ad spending.

Using a special tool on its website, users can view ad spending across 22 countries, selecting across categories (including total media and digital ad spending) and years. With it, eMarketer reports that global digital ad spend will reach an incredible $171 billion next year, a 17 percent increase over this year’s numbers.

eMarketer also feels that mobile advertising will be one of the key factors in growth on the market, according to ClickZ. This is especially true in overseas markets, particularly China and the United Kingdom. Mobile ad spending in the U.S. will increase by 50 percent from the previous year, to an estimated $28.2 billion, which makes up approximately 44 percent of global mobile ad spending. Meanwhile, the other countries will account for 19 percent and seven percent, respectively, in global mobile ad spending. By 2018, those numbers will grow, accounting for 66 percent of worldwide mobile ad spend for those two areas alone.

Japan and Germany are close behind in fourth and fifth place, and users can calculate those numbers using the tool as well. Although smaller in number than other countries, you can see they’ll contribute quite a bit, with approximately $9.61 billion and $6.67 billion, respectively, over the next year. Certainly nothing to scoff at in terms of advertising dollars, we’re sure.