Seems to be a lot of discussion on Weidman's pay which maybe I can clarify a bit.
First, Weidman was on his original contract with the UFC. Being that he is relatively young/new (as some have stated), his guaranteed show/win is not high. He was offered a much improved contract prior to this fight (I don't know exact numbers, but you can safely assume it was at least triple), but he turned it down to instead await the outcome of the Silva fight. His thought was that, as champion (and one who just beat Anderson Silva), he could command a larger salary. He took a big risk and it paid off. So, yes, $24k to show is peanuts, but I expect he'll sign a massive contract any day now.
Additionally, what UFC reports to the commissions is just guaranteed pay. It does not include fight bonuses, sponsorships, percentages and other unofficial payments such as PPV bonuses, among others. It also does not include deductions for expenses such as insurance, taxes, etc. We KNOW that, in addition to the $24k show and win ($48k total), he was also awarded a $50k KO of the Night bonus. Additionally, as a ME fighter, he's probably getting PPV points (a % of the total revenue of the PPV) and an additional bonus for MainEventing the PPV. I'd assume that he probably pulled in at least $1Million for that fight, and will likely be in line for at least $3Million for the rematch (which is already being reported to take place at UFC 168 - the UFC's annual year end show).
Also worth noting if you're into this kind of thing, Anderson Silva's $600k to show is the highest show-pay ever in the UFC.
