I'm going to just go through some PTCs and check out their value:
Sift 1:
NeoBux
-4 guaranteed ads at $0.001 per day = $0.004
-To rent: $0.66. $0.66 / $0.004 = 165 days
-To cashout ($2); $2 / $0.004 = 500 days
-Feel: Feels alright. Little annoying the ads are down in value.
YouCubez
-48 cash cubes at 0.0002 = 0.0096
-To cashout (6); 6 / 0.0096 = 625 days
-Feel: Takes forever (30 min - 1 hr)! Long load time even though ads themselves aren't that high.
ClixSense
-0-12 ads per day = $0.00 - $0.12
-Cashout $10 / ($0.00 or $0.12) = never to 84 days
Feel: It's alright. Occasional annoying ad-breakers.
LinkGrand
-0-8 (approx.) at $0.003 = $0 - $0.024
-Cashout $5 / ($0 or $0.024) = never to 208.3 days
Feel: Meh. Layout could be considered annoying (new page for viewing ad by default), but it's useful for refreshing the page.
BigKahunaClicks
-3-15 (approx) at approx. $0.0005 = $0.0015 - $0.0075
Cashout $0.04 / ($0.0015 or $0.0075) = 27 to 5.3 days
Feel: Feels nice.
Wordlink
-2-4 (approx) at $0.005 (1-2) to $0.01 (2-3) = average $0.025
-Cashout $10 / $0.025 = 400 days
Feel: Feels nice.
AdPaid
-0-4 at .1c to .3c = $0 to $0.012
-Cashout: $3 / $0.012 = 250 days
Feel: Little archaic, not too annoying; very few ads
Clicksia
-about 12-15 ads at $0.001 - $0.005 = $0.012 to $0.075
-Cashout $1 / ($0.012 to $0.075) = 83.3 or 13.3 days
Feel: Slightly tedious security, annoying thing to click at ad end - using adblocker to stop that.
Bux-Matrix
-3-4 at about $0.004 = $0.012 to $0.016
-Cashout $2 / ($0.012 to $0.016) = 166.7 to 125 days
Feel: Hate it. Hard to navigate. But the ads don't take that long...
Incentria
-10-14 at about $0.001 to $0.004 = $0.01 to $0.056
-Cashout $1 / ($0.01 to $0.056) = 100 to 18 days
Feel: Slightly tedious security, annoying thing to click at ad end - using adblocker to stop that.
BuxP
-about 35 at $0.001 to $0.005 = $0.035 to $0.175
-Cashout $17.99 / ($0.035 to $0.175) = 514 to 102.8 days
Feel: Not too annoying.
JillsClickCorner
-approx: 10 ads per page at $0.001 to $0.01 * 25 pages = 250 * ($0.001 to $0.01) = $0.25 to $2.50
-Cashout $1 / ($0.25 to $2.50) = 4 to .4 days
Feel: It's alright.
Rank:
JillsClickCorner
4 to .4 days
Feel: It's alright.
BigKahunaClicks
27 to 5.3 days
Feel: Feels nice.
Clicksia
83.3 or 13.3 days
Feel: Slightly tedious security, annoying thing to click at ad end - using adblocker to stop that.
Incentria
100 to 18 days
Feel: Slightly tedious security, annoying thing to click at ad end - using adblocker to stop that.
ClixSense
never to 84 days
Feel: It's alright. Occasional annoying ad-breakers.
Bux-Matrix
166.7 to 125 days
Feel: Hate it. Hard to navigate. But the ads don't take that long...
BuxP
514 to 102.8 days
Feel: Not too annoying.
LinkGrand
never to 208.3 days
Feel: Meh. Layout could be considered annoying (new page for viewing ad by default), but it's useful for refreshing the page.
AdPaid
250 days
Feel: Little archaic, not too annoying; very few ads
Wordlink
400 days
Feel: Feels nice.
NeoBux
500 days
-Feel: Feels alright. Little annoying the ads are down in value.
YouCubez
625 days
-Feel: Takes forever (30 min - 1 hr)! Long load time even though ads themselves aren't that high.