Block solvers do not get an extra reward.
Kind of off topic, but I think it would be interesting if a pool did provide a small reward to the actual person that find the block. Nothing big, just something to make it interesting and even more of an intensive to have a high overall hash rate to be the finder. Possibly a slightly larger portion of the 25 btc than they would have received.. or half the transaction fee amount gained. The pool would need to of course be transparent as to who the user name or some ID of the finder and the extra reward they received. Surprised no pool as implemented something like this yet.
Not OT, I think...but rewarding the finder really won't accomplish anything except for adding to the op's work, and taking a small bit from all the pool miners...and the pool op. No miner actually "finds" a block by any specific, personal method or effort...it is truly a pool effort...ergo, offering a reward for finding something that one has no control over finding is somewhat illogical. I think that's why it is not used anywhere. If such a reward were being done simply for making the "finder" feel warm and fuzzy, then I don't think I could go along with that. Mining is its own reward. You earn what you earn, and on some days that is really abundant, and on others it is nonexistent...zip. IMHO.
Well, I look at it from a mathematical POV
Same reason why the pool doesn't pay orphans.
Both increase variance and the extra BTC has to come from somewhere ...
Edit: correction - actually they don't increase variance
they reduce it a little and lower the average payout a little most of the time.
In the case of a block reward, the side effect is to reduce, by a tiny amount, the average reward of the majority.
Anyone with a BDR >= 1 gains, everyone else loses a little.
(and of course all the txn fees are already part of the total reward, minus the pool fee)
... and on a complete tangent
Kranium won this weeks ~0.25BTC for having the lowest CDF in the competition on Sunday ... I'll send that today
... but that comes out of my pool fee, not everyone else's rewards