I am planning to have a Paid and a free Lite version of the game upon completion, the Lite version will not feature any ad's it will just have reduced features/modes. (I hate ad's, they make games look ugly and this is my work of art )
This could lose you revenue, you could have 50,000 people "try" your game, aka download the lite version.
When they like the game 2 things will go through there head:
"How much and should I buy it"
Unfortunately most bail at the sight of a pricetag, those 50,000 (this number could be considerably higher...or lower) people could have gained your revenue from ads, making up for the lack of sales from the paid ad free version, money that can be invested in updating it or instead, making something else.
Conveniently placed ads will keep the aesthetic of your game high and users happy.