What is the "right" rate at which my papers should get accepted (to computer science conferences)? In general, when submitting to first tier conferences there is a smaller chance of acceptance but also a better reward.

At one extreme, one may only submit his work to third tier conferences and get nearly all of them accepted at the first shot. Alas, especially for younger researchers, the visibility of these will be very limited and the author might not get recognition for the work at all.

On the other hand, submitting only to first-tier conferences bares a higher risk, especially for PhD candidate looking for a post-doc/position, as it may take several iterations till the paper is accepted and published.

So where should one aim to be in general? Obviously, better papers belong in higher tier conferences, but there may be a goal rate in which your papers should get accepted. If the average number of submissions before accepted is 2/paper (but not all of them are first-tier venues), should one aim higher? If it takes 3-4 submissions but papers end up in first tier venues, should we attempt less competitive venues and publish quicker?



Context: I'm a CS PhD student. My supervisor usually insist on sticking to top-tier conferences even if a paper was rejected 2-3 times. I wonder if it is better to lower the bar after a rejection or two to get my results published faster. From another student here I've heard that they usually get papers accepted in the first attempt, but most of her publications are not in a top ranked conference. What is the right balance here?
To a first approximation, promotion depends on top-tier publications and nothing else. If career concerns are important (and they always are) keep submitting to top-tier venues (as long as you believe the work is good), even if it takes several iterations to get in.  

There's so much variability in what gets accepted that it's best not to take the outcome of any single set of reviews too seriously.  If you start to see a consensus among reviewers as to why they recommend rejection, then of course you will need to address that.  But otherwise, don't lose hope and keep submitting.

Context: I'm a social scientist.