That Wall Street Journal article on Binder and Binder indicates that they took in $88 million in fees for representing Social Security claimants last year which is a lot but that the total for everyone representing Social Security claimants was $1.4 billion. By my math, that means that Binder and Binder had only a 6% market share nationally despite spending $20 million on television ads and an untold amount on search engine advertising.
Binder and Binder's influence goes beyond what its market share might suggest. Perhaps this would have happened anyway but several other firms are trying to operate nationally in ways somewhat similar to Binder and Binder and many other firms operating regionally are also cutting service to clients while ramping up advertising. It looks like a race to the bottom -- who can cut service the most so they can spend the most on advertising.