In the non-paid free version, suggest making the space for the ads in the conversation list fixed or static. The reason being is that sometimes on slower phones or slower connections, I will open the app, quickly look at the conversation list, only to have it scroll the conversations down once the ad finally loads. This has resulted in many 'mis-taps' where I select the wrong conversation or even the ad itself by mistake because there is sometimes a delay in the ad showing up.