Well, setting aside the (very real) potential to create any individual/personal "brand loyalties" amongst a fan base, the key to gaining sponsorship is to be able to provide as much sponsor exposure as possible to the sponsor's desired demographic. As far as NASCAR Cup sponsorship goes, the numbers work out way in favor of sponsoring a Cup car, in terms of total $$ spent and national TV audience exposure time--in seconds/minutes--gained versus paying for commercial shoots and buying 30 sec - 1 min ad slots on TV.
Unfortunately, at present, while the investment in an AMA team is a fair bit less than that required for a NASCAR Cup team, the exposure is disproportionately less--the numbers just don't yield an attractive result. (I'd venture to guess that you could field, say, a Craftsman Truck Series team for the same kind of $$ to run a competitive, albeit privateer, Superbike effort, and gain much more exposure with the CTS team than the bike team.)
As far as Valvoline goes, I'd surmise that it was their very lack of appeal/market share in the motorcycle market that inspired them to sponsor--and continue to sponsor--a MRR team, and, as a fan of the sport, I was glad to see them here and sorry to see them go. Granted, in all honesty, I wouldn't put their oil in my bike (it's not like the Valvoline going into the racebikes was the same sh*t you could buy in the stores, anyway), but, to show my support of their presence in bike racing, I'd just as soon put their products in my old F-150 as I would anyone else's. H*ll, if I were a team owner or rider right about now, I'd be more than happy to tout the virtues of "Aunt Jemima Lubricants" if it ensured putting--and keeping--a bike on the track: "Not good for motorcycles, but GREAT on pancakes." :grin:
Anyway, back to Geoff May--it'll be good to see what he can do on (what should be) some considerably better equipment, and in Superstock, where the overall competition is both better and tighter (than Superbike), IMO.