Fundraising used to require collecting cash and adding it all up to take to the bank. These days it can be much easier. Most charitable events now have online fundraising pages. I have used these myself for a number of events. Social media allows for some fundraising too or at least helps to spread the message. Services like paypal make paying easier, even for folks that might not have a credit card.
Approved charitable organizations can accept donations on their Facebook pages via something called Fundraise by Offerpop. Another Facebook method is Causes, which offers a ton of different fundraising opportunities for your favorite charity.
There is also http://www.crowdrise.com/ and http://www.gofundme.com/ and http://www.kickstarter.com/ and several others.
If you want to raise money for a cause, the online method is certainly an easier way than holding bake sales and car washes, but note that if you promise perks to your donors, it is usually you and not the service collecting the money, that needs to come through with that. Promising perks and than not fulfilling them will lose you credibility and will likely cause you a tarnished image. Only promise what you can and will fulfill.
Adding up the cash did indeed get easier, but before using any method for fundraising, whether you are giving or receiving, make sure you understand exactly what you are doing.