when i msg them, i introduce myself first with something like "i saw [person x] in your tree. [person x] was my [relationship] through [lineage]; are you and i related? if so, i've had my dna tested at 23andme and familytreedna and my results are up at gedcom.com; i would love to compare results!"

that way i'm not just a random stranger asking and they can pinpoint me in their tree before deciding whether or not they'd like to compare.

oooh, that's very cool about the brick wall!

i'll have to check out the isogg stuff on youtube; i didn't know about it.