Have you considered Bulk Mail?
Bulk mail can be used for First Class Mail, Standard Mail and other classes of mail as well.
When you put a stamp on a piece of mail and drop it into your local mailbox, that is “single piece” mail and you are paying full price postage. If you meet minimum qualifications (or choose to utilize a presort mail vendor), you can take advantage of bulk mail rates and save money.
The deciding factor for choosing bulk mail is postage savings.
The USPS offers discounted postage rates for presorting the mail before it comes to them. You are doing a portion of the work for them (such as sorting by ZIP Code), so savings from the Postal Service are passed along to you, the mailer.
Bulk mail may not be the best choice for every mailer.
If you prepare only one or two mailings annually, then it may be best to outsource to a presort vendor. If you mail on a regular basis, but do not meet minimums or elect not to make the time investment in learning to sort and prepare your mail, and a capital investment in permits, mailing fees and possibly software or other equipment, outsourcing to a presort vendor is an ideal solution
Presort vendors are in the business of preparing mail according to USPS rules and regulations. Some vendors will take your mailing from start to finish – design, printing, presorting and USPS presentation.
Should you choose to prepare your own bulk mailing, here are the minimum number of mail pieces that must be met to qualify.
500 pieces for First Class Mail
200 pieces (or 50 pounds of mail) for Standard Mail
50 pieces for Parcel Select
300 pieces for Presorted or Carrier Route Bound Printed Matter
300 pieces for Library Mail
300 pieces for Media Mail
You can learn more about what it takes to prepare your mail and whether or not a presort vendor would be a good alternative for you here: http://pe.usps.com/businessmail101/getstarted/welcome.htm