I used to send my boyfriend pictures while he was working full time, until one day I sent him one while the store was closing. The managers were going around double checking so he and the rest of his (mostly male) coworkers were standing at the door, and apparently 2 or 3 of them standing around got a good view of his screen. They always looked at me a little suggestively whenever I would take him lunch or go in the store after that.
i like to send them to anyone in my contacts who is sexy and knows how to talk dirty. they are very random though. whenever i'm ready to get off and my phone is closer than my computer. may fall asleep on you, may keep you up all night. who knows. when i was in a relationship i would send them whenever i was bored at work so that i would get a spanking when i got home.