In 2011, there is more than 3 millions article in IEEE Xplore
*source 2011 Annual IEEE Report
So, based in this figure alone, we can understand how many conferences has been organised by IEEE.
By estimating 100 papers for each conferences, we could get 2000++ conferences per year
And if each conference generate at least USD20,000. Then we could get USD40 millions per year.
A truly source of income for someone that organize conference so much.
But that is IEEE alone. What about ACM and Springer organised conferences?
We have only 100++ country in this world and that is a minimum of 20 conferences for each country.
So, basically, your paper is going to be accepted not matter where you put your paper.
If some IEEE conference reject your paper, you could send it to other conference since we can check through IEEE Conference Search and found that almost everyday we having a conference.
AS long you can write.
That is the world that we living today.