The Top 100 chart is in for last month, right before Renew Your Vows.
I'll list the top ones and the Spider-Man related ones.
1 SECRET WARS #1 $4.99 MAR
2 BRAVEST WARRIORS TALES HOLO JOHN #1 $4.99 BOO
3 SECRET WARS #2 $4.99 MAR
4 STAR WARS #5 $3.99 MAR
5 DEADPOOLS SECRET SECRET WARS #1 $4.99 MAR
6 A-FORCE #1 $3.99 MAR
7 OLD MAN LOGAN #1 $4.99 MAR
8 DARTH VADER #5 $3.99 MAR
9 CONVERGENCE #5[*] $3.99 DC
10 CONVERGENCE #6[*] $3.99 DC
11 CONVERGENCE #8[*] $4.99 DC
12 CONVERGENCE #7[*] $3.99 DC
13 INFINITY GAUNTLET #1 $3.99 MAR
14 AMAZING SPIDER-MAN #18 $3.99 MAR
15 SPIDER-GWEN #4
16 THOR #8 $3.99 MAR
17 ANT-MAN #5 $3.99 MAR
18 SPIDER-VERSE #1 $4.99 MAR
19 ULTIMATE END #1 $3.99 MAR
37 SECRET WARS 2099 #1 $3.99 MAR
41 SILK #4 $3.99 MAR
75 SPIDER-WOMAN #7 $3.99 MAR
82 SPIDER-MAN 2099 #12 $3.99 MAR
We really haven't had active sales threads for several years, but some interesting things have happened to the industry.
If ICV2 estimates are reasonably accurate, things are better at the bottom.
In April 2015 (May estimates aren't in yet), the 100th best-selling comic sold over 30,000 copies. In April 2011, it was an estimated 17,740 copies.