Hi, Walter here.
There are three excellent channels to reach potential donors. You did mentioned Facebook and Twitter. I will recommend as follows:
1. Pinterest: Sets of two pictures (side by side) conveying the beauty outcome of a donation compared to the actual misery of the situation. Link each individually to a video on YouTube presenting a follow up of each picture outcomes, giving or not giving a donation.
2. YouTube:
A. Link the videos to Pinterest (one of the top 100 sites n the world) so when pictures are click on Pinterest the person is taken to your video.
B. Now link your video to a capture page offering two options to click on, the same Pinterest photos. Ask them... a simple question...ie. Can you guess the age of the picture on the right? (That's the actual condition photo with no donation) A drop box with two options in each photo with the approximate age. One the person clicks on any, will be taken to your website with a personal video from one of those kids thanking for your about to give donation.
It is a 30 seconds video telling the viewer "I will keep you inform how I am doing in the coming days. Ask for the email of the person to send him that updated video.
C. Underneath the email request box, once the email is accepted, place a two option box with a $10.00 and a Can You? box to click on. Once click place the donation page in front of the person.
D. Send an automatic email, once added by the person on the email request page, with the same page with two options as a back up/reminder.
E. Referral: A second email to the person, one week later on Sunday at 9AM and another at 2PM with a 30 seconds video as a follow up on the kid status but this time from you. Show your face and thanks them for the email submission. Report an update of the kid with the photo. A very short video.
F Facebook Fan Page; Create a Facebook page with your face smiley face thanking for the support and placing updates. Sent links to all emails acquired above.
G: Vine: Here is a 6 seconds video... same to photos above, your face and Thanks poster. Place them on the emails out to the list acquired.
There is more to this, but you have the idea. It is a process so you can be know, liked and trust. Once the persons Know, Like and Trust you, your entity, they will be there for you.