Let`s start with Geo targeting that will help you to understand why it can be better to set a low payout offer/product.
Nowdays there are a lot of countries you can promote your offers and sell your product, but is all so rewarding to be so? As you know there are some developed countries as Canada, most of European countries, USA etc., so high payouts can produce results in these countries and in case you are able to target it. But do not forget about the government terms of regulations, many developed countries have very strict conditions so you have to understand the way of promoting your product in this country if it will protect their customers or not? So think about this issue when you promote such products as financial products, forex, alcohol, tobacco, commodities.
But what is concerned about tier3 countries? Anyhow, you can try to promote something to these users too, but the results won't be so successful in most cases, for example tier3 users are not so wealthy. But offer them a free mobile app and the conversion rates will be better. The difference between high payout product and low payout product is very simple: The expensive product attracts a small audience, free or cheap app brings out much more. So even the second one will have a much lower payout, the ease of converting it and the massive volume that you can use. Also, tier3 countries have less regulations, that is why the payouts per conversion will be lower. Clearly, the less regulated this is, the higher the conversion rate will be.
So not least important question is conversion flow. It is the process that turn to successful conversion, you know, that the more you are recieving for conversion, the more profound the conversion flow will be. There are some different ways of Opt in`s.
Clearly, that you can earn more on DOI, but is it really true? You should spend more time to test it and optimize before you will be able to hit the jackpot.
So, you can understand this extremely difference between these types.
The last thing I would like to mention that you need to be aware of that fact that you can get two different numbers in two different networks for the same offer. For example, you own DOI offer and the difference in networks can be about 3$-5$. It means that different networks have disparate publisher and margin policy.
So the last thing I would like to say is be open for business and testing new sources, so now you are on the highroad to success and prosperity.