Google just released its earnings statement for the first quarter of 2015, and the company had another healthy financial period — albeit one that just missed Wall Street estimates. The company pulled in $17.3 billion in revenue, up 17 percent year over year, while operating income of $4.45 billion represented a 26 percent increase over one year ago. That's compared to the $17.5 billion in revenue Wall Street analysts were expecting; Google's earnings per share of $6.57 also just missed expectations of $6.61.

Google's advertising business continues to make up the lion's share of its revenues — but the strength of that business was mixed. Paid clicks (clicks on advertising served on Google's sites as well as partner sites) increased 13 percent year over year, but the rate of increase there has now declined for the 5th consecutive quarter. Likewise, Google's cost-per-click (essentially how much it charges for its ads) dropped 13 percent year over year.

That's part of the ongoing trend of consumers increasing moving to mobile phones, where Google isn't yet able to charge as much as it does for advertising served on desktop sites. Indeed, it's something Google has been trying to address — just the other day, the company announced it would start boosting "mobile friendly" sites when users searched from their smartphones. Google CFO Patrick Pichette did say on the earnings call that strong mobile search was a "key driver" for the company this quarter. Similarly, Google's CBO Omid Kordestani spent lots of time espousing how valuable Google's various mobile apps and Android platform are to the millions of users who are increasingly looking to their phones as their main computing device.

When discussing Google's "other" income, Pichette noted that the 23 percent year over year increase was led by the Google Play store but noted that they experienced a decline in the Nexus mobile device business. During the Q&A, Pichette noted that the yearly decline in the Nexus business was due primarily to the strength last year of the relatively new and updated Nexus 7 — he says the Nexus 6 is not supply constrained and is doing well. Unmentioned was the Nexus 9; it's safe to assume Google's latest tablet isn't selling as well as its popular predecessor.