Considering selling one-off reports with business forecasts or data? One main thing to know is people buy one-offs because they need something that's in it now. Don't push anything that will be updated as a big sales point.

Many new publishers I know make the mistake of saying, "This will include quarterly updates" and thinking that will be a reason to buy. (Plus most newbies vastly underestimate how hard producing regular updates will be.)

Buyers generally want specific data for a problem or presentation they are working on right now and will try to sweet talk your customer service into just selling them that one page. (Or faxing it as a free "sample") So warn CS to be nice but firm.

This is generally a feature-driven sale, unlike most publishing which is benefit-driven. These buyers are seeking X data and you're saying "Here it is."

Your marketing copy should lean very heavily on a profoundly detailed table of contents. Include every single chart name, figure name, and sub-chapter name, not just the main sections.

When I've marketed other author's reports I've often had to go and re-write the table of contents to make it much more descriptive of the data that's included. This is especially critical online where a phrase can be picked up in the search engines so people looking for obscure data will find your report sales page.

The 3rd party resellers who carry these reports will generally split the cash with you, they'll sell onesy-twosies. Biggest mistake most people make is in giving them utterly lame sales copy. A thin paragraph or two of barely descriptive text.
Instead, get as long and detailed as you can.

Put a copyright line, including your online store URL and phone onto every single page of the report as a footer. That way if someone reproduces one page (come on, you know it's going to happen), your information is on it.

Don't set your pricing based on what Forrester or one of the other big brand name analyst firms could get. Their buyers are buying the brand name as much as they are buying the actual content. Unless you're a famous established firm, you're not selling the assurance of your brand name or your relationship with the press. You're just selling data.