$20 CPM rate, is it worth to advertise on a site?

Hello my friends,
I will shortly start to promote my site
and I was/am looking for the best option
for me, based on the audience and my
budget for this campaign I'm about to start.
So, I was looking to advertise on a website
and saw this package:
Type Banner Ad
Size 728x90
Avg Impressions 3,450,000/month
Rate $20.00 CPM
Its a popular website, related to tech news,
downloads, IT, Professional Tech Reviews etc.
What do you people think? Is it worth to advertise?
I would appreciate if anyone could tell me the
probability of clicks/visits that will hit my website.
Im wondering...maybe 80-100 people(for 1K impressions)
could click...
Thank you for your answers!




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