There are a couple things that I need to express to the new developers releasing games OR the developers who are looking to invest in marketing and don't know where to start.
1. Do NOT invest in review websites for your app Honestly, the way the app store is arranged now, reviews are much less visible and if your app is free, users are much less likely to read the reviews because, well the app is free! No risk for the user at all. Also, if your app is done well and you took the time to properly release a quality app, your users will express their pleasure. With regards to paid apps, I do believe that reviews play a little bit more of a factor since you are paying for an app BUT that being said, if you invest in app reviews, for whatever reason, and your app is not good, those users who bought your app WILL vocalize this. So app reviews are redundant to me because if your app is good, then your app will receive the reviews needed and after your app reaches over 100 reviews, whatever your star rating is at that point, it isn't going to change much do to the volume. I do know of the benefit behind being brought up in the search menu but spending 400$ on something that doesn't change the search rank of your app a whole lot seems like a waste of money when starting out.
The easiest way is to simply have an in app rater installed in your app, for free, that goes off every 3-5 visits for your users asking them to rate your app. Doing this will have your heavy users seeing the message and will most likely leave a positive review. Doing this will exponentially increase your reviews initially.
Or you could just create 5 iTunes accounts, give yourself 5 reviews and that's it because only after 5 reviews do the stars show. Investing in "professional reviewers" is a waste of money in my opinion (I was actually running this exact service at one point and not only did we see how invaluable it was, but how much Apple disapproves of these actions. So just don't)
2. Getting told a CPI of $1.00-$3.00 is a fair rate is insane. How can a developer monetize after a campaign when they are paying $1-$3 a download for a free app? The average value of a user for a free app, and I may be wrong so please correct me, is around $0.02-$0.10.
This system only works if you are going BIG. And I'm not talking about 10k, I'm saying at least 50k. Apps like Candy Crush Saga, Hay Day and Clash of Clans are perfect examples of these apps that are investing big and getting it back big due to the high quality of the app, the interaction of in app purchases and advertising and lastly, the organic download that come from being SO high up in the rankings in all of the major markets.
If your budget is around 1-5k, you should be spending around 0.25-0.33$ per install. Systems like AppGeneration (apps that promote other apps and I have used many times), Facebook (use all the time in smaller markets) and some specific blogs that have good local exposure (iphoneitalia, appshopper etc.) are great ways to spend little and get back a lot more, which then makes it easier to have continuous users instead of risking your years budget in hopes of a touchdown with other services or affiliate networks. 3. Using companies that are mobile marketing experts, or will advise you pre and post launch are NOT worth it. Using these I see these companies everywhere, stating that they have a "robust" system where they give you expert advice on which markets your app is best for and blah blah blah. This is ridiculous. Here are some free tips about what to do before you launch your app. TEST, TEST, TEST. The more testing the better. And I don't mean you, I mean random, regular people. They will interact with your app in ways you never would have since it is yours.
Next, launch that baby! You get organic exposure regardless for free, so why not see how it goes first before you launch it.
Listen to early reviews. If you are getting 1* reviews everywhere, you got a problem. If people aren't saying anything, this isn't a bad thing either, it means they have nothing to complain about.
Lastly, have a strategy to monetize. Whether it be a paid app or an interactive app with IAP, have a clear cut way to monetize WELL before you launch.
All of the things I have posted here are my opinion and I love to discuss new, old and original ideas. I say these things so people do not make the same mistakes I have made in the past and save some serious cash and headaches. There are a lot of fantastic systems out there that are genuinely in place to help you with your app. Others, like I stated before, are not and are simply in place to rob you.
But one thing I can say is this. No matter how much money you invest in an app, and how much you try and push it, if it is a BAD app, people will not like it. So take the time in making a quality app and if you are strategic and get a little bit of luck, you will have great success!