In our daily digest of postings in Give and Take, the Chronicle’s roundup of the best blog posts about the nonprofit world, we note:

• An effort by Yahoo to persuade people to voluntarily put a one-cent stamp on outgoing e-mail messages, with proceeds going to charity.

• Questions about the long-term impact of efforts by Muhammad Yunus, the microfinance pioneer, and Hernando de Soto, a leading advocate of property rights for the impoverished.

• Five steps for an effective social-media strategy.

• More on the debate over how much charities should have to prove their effectiveness to donors.