How about a 3 week race series. Payout to the top 10 each day. You have to run each day's race and make a time cut, maybe within 10% of the winner, to be able to start the next day's stage.
If nothing else, it'd be the best training camp of the year for a lot of people. $100 buy in per athlete.
Below is what I'd posted a few months back in a tour de france equivalent running race. Two distances are listed each day, the first being what cyclists raced in the tour, the second being the running equivalent in terms of stress the body can handle running.
It would be different, and exciting, and I feel runners could begin to see the value in running hard many days in a row. This would not set any WRs, but it would set some guys up to set WRs several weeks later once they absorbed all of this work.
1 Individual time trial Saturday, July 4th Utrecht / Utrecht 13.8 km - 2.0 km
2 On-line Sunday, July 5th Utrecht / Zande 166 km - 24.2 km
3 On-line Monday, July 6th Anvers / Huy 159.5 km - 23.3 km
4 Hilly Tuesday, July 7th Seraing / Cambrai 223.5 km - 32.6 km
5 On-line Wednesday, July 8th Arras CommunautUrbaine / Amiens Mropole 189.5 km - 27.6 km
6 On-line Thursday, July 9th Abbeville / Le Havre 191.5 km - 27.9 km
7 On-line Friday, July 10th Livarot / Fouges 190.5 km - 27.8 km
8 On-line Saturday, July 11th Rennes / M-de-Bretagne 181.5 km - 26.5 km
9 Team time trial Sunday, July 12th Vannes / Plumelec 28 km - 4.1 km
- Rest day Monday, July 13th Pau
10 Mountain Tuesday, July 14th Tarbes / La Pierre-Saint-Martin 167 km - 24.4 km
11 Mountain Wednesday, July 15th Pau / Cauterets - Vall de Saint-Savin 188 km - 27.4 km
12 Mountain Thursday, July 16th Lannemezan / Plateau de Beille 195 km - 28.5 km
13 Hilly Friday, July 17th Muret / Rodez 198.5 km - 29.0 km
14 Hilly Saturday, July 18th Rodez / Mende 178.5 km - 26.0 km
15 Hilly Sunday, July 19th Mende / Valence 183 km - 26.7 km
16 Hilly Monday, July 20th Bourg-de-Pge / Gap 201 km - 29.3 km
- Rest day Tuesday, July 21st Gap
17 Mountain Wednesday, July 22nd Digne-les-Bains / Pra Loup 161 km - 23.5 km
18 Mountain Thursday, July 23rd Gap / Saint-Jean-de-Maurienne 186.5 km - 27.2 km
19 Mountain Friday, July 24th Saint-Jean-de-Maurienne / La Toussuire - Les Sybelles 138 km - 20.1 km
20 Mountain Saturday, July 25th Modane Valfrus / Alpe dHuez 110.5 km - 16.1 km
21 On-line Sunday, July 26th Sres - Grand Paris Seine Ouest / Paris Champs-yss 109.5 km - 16.0 km
Total Miles/Km Cycling = 2088/3360 - Running = 305/490
It averages out to racing about 100 miles per week.