1. Publish a product that's better than competitors'.
2. Open source it.
3. Earn the cheers from the free software crowd, and get the advantage from external contributors, as only large browser vendor.
4. Your users will love the freedom they have, and your product will be famous for its extendibility. They'll love ad-blockers as the web gets more and more annoying ads.
5. Get more and more market share by staying better than your shitty competitors.
6. Let other browser vendors copy your success by open-sourcing their browser as well, or giving up to EEE the WWW.
7. Start your downfall:
a) Require add-ons to be signed because we live now in a world of apps and every app is is signed.
b) Publish ads in your product's start page. Enjoy the annoyment of your users.
c) Integrate an useless closed source product. (Pocket). Enjoy the annoyment of your users.
d) Announce that your addon API will be locked down.
e) Publish your "principles for content blocking". <====== We are here
f) Enforce them. This is the point of no return.
8. Gently shove a Yoda Doll up your user's asses. Be careful, its larger than the dicks the other browser vendors ram up their ass as well. That's also the only reason your browser is still used.
9. Enjoy your 2% market share.