Ad Companies and the 20k Minimum

RAD-INFO has worked with Adzilla to present its unique revenue stream to ISPs. And now we have met BareFruit to do the same. However, these companies are looking for ISPs with at least 20,000 subs. How many of those size ISPs are left? The WISP List's Top only has 7500 subs. Other than EarthLink, AOL, NetZero, the Tele-Barons and the CableJockeys, how many other ISPs have 20,000 subs? (Might depend on you define subscriber, huh?) I'll ask around today at ISPCON.