I think that is a interesting comparation...

YEARLY SALES

Year
launch		468,888
1	13,250,962	9,613,346
2	14,112,182	9,488,584
3	14,369,898	12,814,297
4	9,745,610	14,048,403
5	1,913,102	9,855,987
6		9,243,328
7		7,459,539
8		4,220,108
9		2,973,884
10		391,786

LIFETIME

Year
launch		468,888
1	13,250,962	10,082,234
2	27,362,244	19,570,818
3	40,416,789	32,285,115
4	50,104,123	46,433,518
5		56,289,505
6		65,532,833
7		73,171,078
8		77,314,350
9		80,288,234
10		80,680,020

Considering that the Vita is the second biggest competition a Nintendo handheld has had, the PSPs 80M is fucking impressive!

PSP, 3DS will have shorter life than PSP.

I'm really impressed that the PSP managed to sell more than 14M in a year only. It was really a beast for a new handheld.

Well, the 3DS had a better start but has started the decline eariler and a lot more brutally; that drop from around 14.4 million to 9.75 million is downright nasty, especially being one year earlier.
The 3DS won't hold as well as the PSP did in the twilight years, the DS and PSP were products of a different time on the market, the mobile revolution has come like a tidal wave since then.

I think the PSP will have more sales lifetime; the 3DS' decline will simply be too steep to maintain high enough annual sales, I expect it to be a bit below 60 million at year's end, leaving another 20 million+ to cross 80, I don't see it happening at this point.

PSP > 3DS

I think 3DS will decline faster than the PSP did.
It did have a strong start though.

PSP had better support then PSV and 3DS support combined

PSP was a late bloomer, I don't see the 3DS matching late life sales so I'll give it to the PSP. Either it will be close.

I think the 3DS will do a minimum of 70m-max of 80m.