I agree with @MadelineStefanou . Customers don't consider the true costs of what they are doing, especially with this function. One of those costs is the time spent by employees to maintain that ""small and manual"" solution. That staff could be doing something more relevant to the bottom line to more than offset the WSP investment. Data control and security are other costs that should be considered, and who can really assign a cost to those when they are compromised.
IN-SYNCH may be less of an investment, but requires more internal intervention than the WSP ""turnkey"" solution.
Then there are those customers that evolve their solution, so they are implementing different solutions. Because these are implemented over a number of years, they don't realize what they have spent. Just start with WSP and it's done. Resources can the be deployed on more important projects.