Top titles are seeing a “steady decline” in the number of in-app purchases made, indicating a struggle to maintain the momentum that saw them leading the way in 2014.

According to Return Path, which describes itself as a “global data solutions provider”, the trend is impacting games such as Machine Zone’s Game of War, Supercell’s Clash of Clans, and King’s Candy Crush.

But there is an upside: while the number of in-app purchases have declined, revenue has been “buoyed” by bigger orders.

“This may reflect game companies’ strategic shifts to focus on their most engaged players for their in-app revenue, or a broader trend among users as dedicated gamers invest in their passion while more casual players lose interest and spend less,” Return Path wrote.

As an example, Game of War purchase numbers declined by 21 per cent from January to March, despite an extensive advertising campaign featuring model Kate Upton. Contrastingly, average order values increased by 9 per cent in February and an additional 21 per cent in March, offsetting the volume declines.

And for Clash of Clans there was a 27 per cent falloff in order volumes during the quarter, although the total sales decreased by only 3 per cent.

Return Path’s analysis is based on purchases made by “approximately 18,000 US consumers in Return Path’s panel of 4 million email users”. Games included were Candy Crush, Clash of Clans, Farm Heroes, Game of War, Hay Day at Pet Rescue.