Is there a reliable service/SDK that will let me provide an item & location to get fulfillment information?

Re-visit your marketing strategy. Which is to say - re-visit your business model (which should very directly point you in the direction of your highest probability marketing strategy). And (get ready to not like me for saying this...) stop focusing on those numbers. The number of visitors per month and the number of downloads are only relevant as they directly relate to conversions and sales. And those things are only relevant as they directly relate to bottom line revenue and margins. It's easy to get caught up in "vanity numbers"... those numbers that "feel good" and provide you with a sense of validation. But until and unless they translate into bottom line income for the business they are just numbers that make you feel good (versus wisely chosen key metrics that indicate the health and viability of your business). If this was helpful to you please let me know how else I can be of assistance.

Freemium revenue for mobile apps was up 211 percent last year (2013), according to a report from mobile analytics company App Annie and IDC. 83 percent of the top thousand apps on each of the iOS app store and Google Play — monetize via freemium, an even bigger proportion of revenue generated by those top 2,000 apps arrives via freemium: 92 percent. Naturally, the key to success as an app developer who uses the freemium model is getting as large a percentage of your free users buying something as possible. That’s a significant challenge. You have to do what makes the most sense for your app and the users on it. You must create value for the user and make it compelling for them to spend money on whatever you plan on offering. In terms of viable it is tough to say because I don't know what your medical app does. 1. Look at the data from your app 2. Talk to your users about what they want 3. Look at what your competition is doing or others in a similar vertical

One thing I like about your question is the fact that you're ASKING it. Trying to quantify profit. Most people never even get that far. They treat profit--especially if it is that of their own business--as some ethereal thing they will "get later" if possible. "To manage we must measure" is a business maxim and a fundamental one for me. If we don't build Profit into our revenue equation, we're unlikely to get any. And so asking this question and building profit right into your revenue target is a powerful idea nearly all small business owners totally miss. As for an answer...that amount is really up to you. What do you need to survive? There are so many variables we don't know about: what kind of business, what scale, what paths to market are you using, etc. etc. that affect costs, together with the price tolerance of your marketplace, that it's not possible to give an "average" answer. When I train business owners on how to set their operation up for success, I recommend 20-30% of revenue be built in as a monthly amount for profit. However, this is usually for consultants, and may not be possible for other business models. Sometimes 5% profit is what's achievable, say for a commodity provider, and if they make money with that, OK. Have you done any studies of comparative firms in your niche?

I guess the best answer is, it depends. What kind of mobile game are you marketing? Who are you targeting? For what platform? (iOS, Android?) Different ad networks work better than others depending on the type of game. A good place to start would be MoPub, MDotM, Manage, and Insight.

Your pricing model should hinge on the fact that the perceived value of services should outweigh the cost associated with it. You can consider looking at online marketplaces like Craiglist, Kijiji, Airbnb, etc to understand various types of business models. However, the approach shouldn't be based on what others are doing. Rather, you should understand your niche, values associated with the niche, and adopt appropriate pricing model. Invest your time in designing the business model for your startup, followed with reviewing it vis-a-vis other models. Need help with business model? Feel free to reach out.