Are those photographer trying to offer me work or are they trying to sell me portfoglio pictures?? who's advantage is benefited here?

my jock strap photo is very popular. I guess undees are my think. I prefer suit modeling , though

frank

if i want to shoot with a model i generally message them directly or respond to their casting call. a friend request (especially from a non-local photographer) is a bit too vague for arranging a shoot.

i get a lot of friend requests from traveling models who are looking for paid work and retouchers who are also looking for paid work.

generally a model will friend me after we've worked together.

It's hard to know why they are friending you, they might be interested in working with you, or calling attention to their own work, or even just trying to pad out their friends list with more people.  When I get a friend request from a photographer, especially one in my area, I like to tag their profile thanking them, and asking them to let me know if they are casting for a model.  It's been working well for me so far.