I posted on this thread over 3 years ago on our opt-out program. We have since expanded it into our middle school as well. I definitely think that the success of a direct donation option depends on your school community. For us, it continues to be successful with annual donations at each of our 3 schools averaging between $5K -$6K per year out of a budget of about $25K-$30K.
We still rely on traditional fundraisers to bridge the gap. As dlf posted above, you need to let you families know what your goals are and that translates into participation whether it is volunteering and/or contributing financially.
I've never seen opt out programs or donation programs as very successful. We had a boosters program for businesses and through MUCH sweat from our fundraising chairperson and MUCH generosity of a few of our families that owned businesses, we did raise about 3,000 dollars. But in reality, a good communication program with your parents, that lets the know and understand how and why you're raising money; one that allows them to buy into your group and feel like they are a part of the goals for the group will bring in tons more money than that.
We were able to routinely raise 30-40k a year, and another 14-17k in classroom donations for our school. Now-we had a huge demographic; one that spread the "wealth" if you will from our doctors on down to our rural, poor, poor families. BUT, when asked for the right reasons, even the families that we in turn supported during the holidays, sent in their money to get the payback associated with feeling like they'd made a difference.
How do you do that? You let EVERYONE know EVERY chance you get, what your goals are. You send out emails, write newsletters, speak at every school event and get your hand out to shake hands, every chance you can to inspire people to be a part of your team. You learn their names, you learn their children's names, you send home emails that talk about "special" things you've witnessed in the halls and you take the parents to that world. Let them know you watched a teacher invite a former student into their room so they could wipe their face after the child had sneezed; or that teacher that stopped one of the children in the school that they've NEVER taught, from losing their breakfast tray by taking the time to stop them in the halls to rearrange everything.
THAT's how you build a team...THAT'S how you inspire...and frankly, THAT'S how you get contributions.
Our school successfully did this a few years ago. It was promised that there would be no fundraising if the parents collective giving reached a certain amount. That promise resulted in a big turnout because it was so enticing to not have to do the cookie dough and all the other stuff........the first year. After that, the donations slowly declined until fundraising had to kick back in.
We are contemplating the opt out system right now. Every Family is already required (private school) to pay $15 dues a month so that helps. But we have a lot of families that do not participate in the fundraisers and it hurts us especially since we do not get funding we need all the money we can get.
We started an opt-out program in our 3-5 school three years ago with phenomenal results. We have a very ethnically diverse population and only half of our families participated in our main fundraiser (gift wrap). With opt-out being added, we've found that gift wrap sales dropped only slightly. Last year this school made over $5000 in direct donations and it seems to grow more popular every year.
This year we have our K-2 and middle school also instituting this fundraising option. One thing I do is to include a note with the receipt that lets parents know that they will still receive fundraising materials with their child but can ignore them if they chose to opt-out.
As far as a suggested donation, we divide our projected income by the number of students. It generally falls areound $40-$50 per student. Many parents send in this amount. Some send in less and some more. Remind them that it is a tax-deductible donation - that may help. We also send out a reminder before winter break in case any parents want to send in a donation before year-end.
This is only ONE fundraising choice we offer. We still do gift wrap, pie & cookie dough, etc. I think that a mix still works best - some traditional fundraisers along with direct donations.
Last year we gave our parents the choice to make a cash donation instead of fundraising. We only took in $310 in the opt-out, and making sure we didn't send home fundraiser info with Little Suzie was a pain. Heaven help the fundraising chair who accidentally sent home information to that one parent who had paid not to receive it. This year we are giving parents the opt-out option with each fundraiser instead of for the whole year.
This year we are giving parents the opt-out option with each fundraiser instead of for the whole year. 
