There may be a difference because of whose money you are spending. Some people would say that people will act differently and buy differently based on whether you are spending your money or someone else's.

I'm skeptical.

I don't think that people's fundamental natures and behaviors are nearly that variable.

We like to think that the B2B experience is all based on facts and ROI and benefits and hard data -- while the B2C experience is all about image and status and service.

As I've seen it, B2B is virtually the same as B2C. It's 90% emotional, irrational, and gut-level. Service and attention count for a lot. The only difference is the B2B buyer needs something to justify his emotional, irrational, gut-level decision to his superiors. So give him some numbers and facts to send upstream if needed.

But then I'm only a writer.

There are some basic parallels but there are some very different stimuli to buying.
B2B is usually done with proper application fit, the buyer is keener to the marketplace and what they need to help their profit package, what their customers require, and what (and how) their competitors are solving this problem.

B2C has much different stimuli to buy. The brand has much to do with buying patterns. The season, how consumers feel about the state of their security, credit, economy, etc.

Having spent a significant amount of time in both arenas, I see the major difference as being the expectations that the consumer brings to the transaction. B2B consumers expect the experience to be based on relationship and soft-skills more than environmental factors that are tactile or sensual. B2B consumers have a tendency to view environmental extras as frivolities that are going to needlessly cost them more. B2C consumers on the other hand expect "extras" to be included in the transaction and related to building value, where B2B consumer expect "extras" to be separate from the transaction and related to building the relationship.
This is not to say that B2B and B2C consumers do not have many of the same expectations and motivations, but their expectations for where to place emphasis vary greatly.

The experience that B2B and B2C customers have is also reflected in the software systems that businesses have used in the past, sometimes having 2 separate modules to facilitate each market place. In my experience older systems that have targeted a B2B audience are very much geared around flexibility of placing and amending quotations and orders, quite often having very few restrictions in place on the operator because in the B2B customer-supplier relationship is an ongoing affair and the supplier needs to be far more accommodating. Also a big difference is hard allocation of stock so that when you promise your best B2B customers stock it is still there in one week, whereas a lot of B2C operators will operate on a first come first serve basis.

Over the past 5 years or so I have seen a big trend for B2B suppliers to move into the B2C arena - quite often because of better margins. This has lead to software systems needing to be for more flexible than previous and be able to accommodate both a B2B and B2C environment.