It is a great website with tons of sheet music. I have recently signed up for the Digitial Print Publishing program to sell some of my sheet music online and have already made my first sale. I was a little nervous about signing up, because I didn't entirely understand the process, so I wanted to alleviate any concerns for other composers that might be interested in looking into this.
All in all, I found this process to be very simple. You can sign up at https://digitalprintpublishing.sheetmusicplus.com?referral_id=492445 (this particular link will list me as the referrer, so I would appreciate your using it, if you find the information on this blog useful). Signing up is entirely free. After signing up, you can upload sheet music as a PDF and may also submit a sample audio MP3. After uploading, you will be asked to provide a general description of the piece and certain information about instrumentation and copyright information. Once this information has been submitted there is a 7-10 business day processing period, after which (if everything is found to be acceptable) your music will appear for sale on the SheetMusicPlus.com website.
Also, you can simply sell audio MP3s. The only drawback I see to selling MP3s through this site is that they sell for $1.99, which is considerably higher than the typical $0.99 MP3s found on iTunes. The advantage to selling MP3s through this site is that there is no setup/registration fee as is generally found on other MP3 sales sites.
The Dashboard on your Digital Print Publishing account page will show your sales for the month. You receive payment on a monthly basis when your sales have reached your payment threshold (which can be set to $20 as the minimum amount). You may remove your PDFs or MP3s at any time, and may change them at any time, although the latter will require another 7-10 business day waiting period.
If you have any other questions, please post them in the comments section. If you are ready to get started selling your sheet music PDFs or MP3s at SheetMusicPlus, then click here: https://digitalprintpublishing.sheetmusicplus.com?referral_id=492445