The threats everyone made against SOPA, or against Godaddy's support of it would have been even more effective if there had been a way to give them more credibility. Lots of people actually switched providers, but many more just said they would if it passed - and Godaddy probably just ignored a lot of them.
What about something like a reverse Kicksterter, a way for people to legally bind themselves to follow through?
I have heard about the phone application which identifies products sold by supporters of SOPA, and lets you know so you can avoid buying them - but what about if your credit card did this? When you went to charge something, before you did, it had the option to warn you if any of the products are sold by companies you disagreed with?
Now, imagine a Kickstarter-like version of this - you could pledge (in a legally binding manner) to your credit card company that it would not let you buy any products from supporters of something you didn't like (given some conditions). And this real legal pledge would be delivered to the companies.
Imagine in the case of cable companies - being able to make backed up threats to cancel your cable (or pledges to buy more products) contingent on certain actions taking place. Or imagine being able to send legal proof that you have instructed your credit card to irrevocably prevent you from ever buying a product from a certain company. Think how scared that company would be!
Imagine a petition - but where you have the option to give it real economic force. Say the petition is that a certain cable company formally renounce support for a law currently being debated. If you signed it, there'd be an option to legally promise to cancel your cable subscription unless the company did what you wanted. And it would only take effect if at least 10,000 people signed the petition, so you could sign it freely without worrying about being the only one to boycott.
So you could deliver a letter to the company, not with just threats, but with real guaranteed action - action already in line to take place unless they reverse course.