Don't dump paper
The Indy 500 Mini-Marathon, in Indianapolis IN, charges an extra $5 to people who submit paper entry forms (see #24 on the form).
While it's a good idea to drive people to online registration (it costs the race less, even when absorbing surcharge fees), don't dump paper totally.
You still need to promote your event by distributing information at races, running stores, health clubs, and anywhere else that might help.
A flyer, post card, or brochure without the application portion is very helpful.
Most people who register online first saw the information in paper form. Many like receiving paper, even though they are likely to register online - especially if you give them a discount for doing that.
NOTE: Never rely on only one venue for promotion. Use as many different marketing vehicles as possible to attract entrants.
