Time/Impressions to judge a network

Since we are getting bombarded with ad networks. Its good to share how much time/impressions do you wait before ditching an ad network.

7 days/5000
14 days/10000
21 days/50000
30 days/100000 (by this time, most of the users would have upgraded to new version of app)

For me I think 5000 impressions are enough to judge an ad network. What abt you guys?

Yes i do agree with you, some ad networks might say that i can take a full month for them to analyze and serve you better ads for your audience, that might be true, but if you start with the said network with a very low eCPM then it´s likely it will not get any better.

I give it couple days, sometimes a week.