Highest open rate subject line possible?

On my old SDR team we used to joke about what would be THE BEST performing subject line for opens. Doesn't have to get replies, just needs to be opened. Below are a few of my very favorite options we came up with. Note: we never used any of these.


"Your son bit me"


"You are OVERDUE"


"I know what you did..."


What would you use if you HAD to have your emails opened?

😂 Sales Humor
5
fuzzy
Notable Contributor
4
CMO (Chief Meme Officer)
"I have your kids."
funcoupons
WR Officer
2
👑
"Don't open this"
salesnerd
WR Officer
2
Head of Growth
Maybe even add a "CONFIDENTIAL" beforehand to really seal the deal.
CadenceCombat
Tycoon
0
Account Executive
Bold
sellout
Good Citizen
2
Hybrid Account Executive
“I’m Pregnant”

Kidding, but funny thing is my actual best open/success rate comes from an email with subject “this could be us...”. I sometimes put in that gif of Leo in WoWS throwing the money off the boat. 
tonysoprano
Big Shot
1
Sr. AE
open for a surprise
DaveFromCollege
Notorious Answer
1
Account Executive
We didn't use this much but had an external sales training and the most opened email subject line was:

Busy?
harrypotter
Big Shot
1
Chief Muggle Officer
{Name}, your recent acceptance to Hogwarts School of Witchcraft & Wizardry
YoungGoat
Opinionated
0
Surgical Technology Specialist
"how dare you"
CaneWolf
Politicker
0
Call me what you want, just sign the damn contract
One of my teammates in my BDR days suggested "Your wife's stepping out on you" would be opened 100% of the time. 
KomodoDragon
0
MDR
Hey (name), quick question. 70-85% open usually
Omar
Executive
0
Enterprise Sales Executive
This one is simple it's
"Re: Meeting Next Week"

it will get opened and likely get a response; albeit maybe negative but a guaranteed response 
Carlosg
Politicker
0
SDR
How about "Calling you Tomorrow at {{Phone Number}}"? This may increase the reply rate as they would try to avoid this call.

What do you think?
2

Email open rate

Discussion
8
6

When finding both Mobile and direct lines for prospects, which number has a higher success rate?

Question
7
Better Connection/Success Rate
73% Mobile
27% Direct
79 people voted
14

Using the prospects first name in the subject line helps with more open rate?

Question
22