This month we finally can report a slight drop in the numbers – in both mobile marketing costs and app downloads – which may come as a welcome relief for marketers. App install volume of the top 200 free iOS apps decreased 17 percent to 6.7 million, according to the Fiksu App Store Competitive Index. Along with falling downloads were declining costs, as May’s cost per loyal user of $2.47 was down 10 percent since last month.

As the proverb goes, “April showers bring May flowers,” and the same may be true for marketers in April. While this past month represented another expensive one for mobile, particularly on a year-over-year viewpoint, it also may prove to be very fruitful. As leading brands heightened their focus on strategic mobile spending and higher-value targeting, loyalty rates of app users (and the cost to acquire a loyal user) has improved slightly.

This month was a significant one for the Fiksu indexes, as it marked the first time in history that the cost to acquire loyal app users (CPLU) surged passed the $3 mark. While hitting a historic high, this number isn’t surprising since it points a larger trend of rising costs and steadily growing competitive pressures observed across the landscape.

Our newly launched January Indexes revealed the aftermath of the 2013 holiday season, during which app marketers fought for the attention of the masses of eager new device owners.

The new Cost per App Launch Index was just $0.16 on both Android and iOS. Converging for the first time since February 2013, this rare occurrence is likely a post-holiday “correction” following the big brand budgets spent around the holidays, especially on Android.

It’s been a memorable day for Fiksu, as we reached another notable milestone! As of April 30, 2013 – two years since our launch – the Fiksu Mobile App Marketing Platform has recorded its one hundred billionth app user action and has driven more than one billion app downloads. This data is critical to our ability to drive real-time mobile ad campaign optimization and deliver the high-performance marketing results that leading brands demand. It’s also the foundation of the Fiksu Indexes and our insights into the complex app marketing landscape.

Following the momentous iPhone 5 launch, which prompted a period of cost-efficient marketing and heightened organic searches, we observed a dramatic U-turn in November as holiday season spending accelerated and mobile app marketing costs jumped.

Last week, Apple’s highly anticipated iPhone 5 started hitting the shelves, selling a record-shattering 5 million units in its first weekend of availability. Additionally, more than 100 million existing iOS device owners have already rushed to update to iOS 6, Apple’s newest operating system. But, for several weeks preceding the arrival of the iPhone 5, we observed a change in consumers’ download appetites, reflected prominently in our new August Index numbers.

Writes Thomas Hazlett for the Wall Street Journal: "On June 29, 2007, thousands of fan-boys and-girls camped in long lines to inhale a wisp of sweet techno fairy dust. The new iPhone rocked the world. Revolutionary in design, function and ecosystem, it set off the mobile data tsunami. In three days, Apple sold a million of them."

Our April Fiksu Indexes indicate that mobile marketers began picking up the pace as they moved out of the first quarter, a historically quieter period of time for app development and promotion, into the busier second quarter leading up to the summer. In particular, marketers aggressively sought new opportunities to compete for ranking in the dynamic social networking and games categories which experienced volatility during the month.

Here’s a snapshot of the latest data:

Following January's sky-high download volumes available at rock-bottom prices, February presented a steadier and more normalized landscape for mobile app marketers.

Here’s a quick snapshot of the February Index data: