Manually removing the background from a photo is definitely the best option, but it takes skills and the right applications.
A good image editor can do a great job, but many users do not have computers, or do not know how to operate it.
Remove.com is a new service that is currently free of charge. The service automates the background removal process.
Just select the photo you want to edit, upload it, and click button download as soon as the editing is complete to download the edited photo to your system.
The processing time is relatively small, but it depends on the size of the image.
Remove.bg removes the background of an image by trying to crawl a person in the photo. The service can only find people in the foreground, and can not be used to remove the background from photos with objects.
In addition to the online service there is also an application (new version 1.4.7) which you can download from here for Widows, Mac and Linux.