How does Quora.com and Wikipedia measures their monthly active users?

There are three types of metrics that you want to collect. 1) Aggregate metrics 2) Cohort metrics 3) Funnel metrics A tool like Flurry is OK for aggregate metrics. Google Analytics for mobile is probably the better choice depending on your needs. For cohort and funnel metrics, I prefer using Mixpanel. And for tracking App installs I prefer Tapstream. For a deeper dive into the above analytics types above, I recommend reading Lean Analytics by Alistair Croll and Ben Yoskovitz.

There are some market-research companies which have very detailed sector specific knowledge. Thus, they are not freely available for consumers. Here are a few to get you started: http://www.mintel.com/ https://www.marketresearch.com/ https://www.marketresearchreports.com/ https://www.ibisworld.co.uk/

You'll find that looking at top line revenue alone won't provide much value to you if you are asking the question "Is my advertising spend worth it?" Typically, in advertising I want to know the Lifetime Value of the customer or the Average Revenue Per User (ARPU). Then, it boils down to : If I spend $100 to acquire this new customer and he spends $150 over the lifetime of his paid relationship with me then, yes--- my ad spend is worth it. On the other hand: I could spend 10K this month in ads. I could sign up 20K in users/customers/top line revenue. But my data will tell me I spent MORE per customer/user than they are actually worth over the average lifetime. So that's what usually answers the "Is it worth it" question in any advertising scenario. 1. How much to acquire the user? 2. How much does the user spend over the avg lifetime? If it doesn't make sense, it's not worth it, regardless of what your top line revenue tells you. You might find this blog post on cohort analysts valuable as it goes into more detail. (I have no affiliation.) https://apsalar.com/blog/2012/01/how-to-use-cohort-analysis-to-improve-revenue/

I think push vs in-app are two different things, like email and telephone call. Push reaches people who are not using your app, but require OS-level permission. In-app gives you much more flexibility but they only reach people who are using your app (obviously!). As to whether in-house or external SDK is best, it depends what you are trying to do and whether an external system handles it. For a typical retail environment the SDKs might be easiest--it's a well-established use-case. For something needing a more customized algorithm, an in-house system might work as well as an external SDK (for less money). There are simple options to save you from starting completely from scratch, from PHP toolkits to Amazon SNS. It depends on what (if any) server environment you have... Hope that helps!

Try Intercom.io You get visitor level information on how active they are etc.