What are examples of "give away the razor, sell the razor blades" type of businesses where companies sell the initial product at a loss and hope to make their profit on subsequent recurring purchases?

Although I don't know enough about the sector to say that first product is sold at a loss, a lot of Business Intelligence software such as SAP, BPCS etc come to mind. The initial purchase of the software is only the beginning. Then follows the constant flow of licenses and, most depressingly, the hired consultants to customize the software to you particular business.

How about lawyers who will draft a will for $100, hoping that they can later charge much more to do the probate?

I believe the opertative term is "installed base businesses" Microsoft's strategy was to price low, set the standard, achieve ubiquity and then harvest profits from upgrade/ revision revenue.

One could argue that Amazon Prime is an example. Stapler : Staples

Nespresso is doing great at selling the razor and selling the razor blades with their capsules.

Anti-virus Software Subscriptions. Braun Electric Shavers with their cleaning cartridge. Pneumatic Nail Guns.

Some on line advertising companies will build you a 15 page web site with custom copy and do SEO without a contract for 250$/per month, or less. The lower you go from 250 the more it looks like a directory listing.

Lexis, Westlaw, and BloombergLaw all make full-access research accounts available at no cost to law school students, and even offer rewards points to students for using their product, an embedded employee at our school called an "Account Manager" and each also employs student workers to be available as a resource, all in the hopes that after law school the new lawyer's preferred research tool will be their product, so that they can make money off the lawyer's future use of the product.

Starbucks. They give away quiet, hip space in places with lots of foot traffic, but sell marked-up coffee.