Some sites having annoying ads, or adblock removal nag screens. The most annoying have these ads or nags in a div with a random number on the end, so blocking it does no good. What you need in this situation is to block with a wildcard.

After some searching and referring to quite a few forum posts I came across this –

www.annoyingwebsite.com##div[id^=”start_of_div_name_before_number”]

Just find the div you want to block, find the non-changing part and modify the above as necessary.