The city of Seattle itself is, in the main, served by two transit agencies - King County Metro, which provides service in Seattle and its immediate suburbs, and Sound Transit, which coordinates intercity express buses and the Sounder commuter rail system and runs the new light rail line. It's the first instance I've encountered of a city's rapid transit system being run by a system other than the one that runs the buses - it's like if the Toronto bus and streetcar system was run by the TTC, but the subway was part of Metrolinx and ticketed separately.
It's the fares that really act as a disincentive for me - not that I don't want to pay them, but that the system seems almost engineered to be as difficult as possible for casual riders to use. Sure, there's a ride-free area around downtown, but only between the hours of 6 AM and 7 PM. So far as I've been able to find, the boundaries aren't posted on buses - just on some of the downtown maps - and none of the buses I've been on have had automatic announcer systems, so unless that was just a conincidental technical fault, you'd better hope the bus doesn't take you out of the zone before you realize it.
Then there are the regular King County Metro fares - $2.25 off-peak all zones, $2.50 peak one zone, and $3.00 peak two zone, with the zone boundary fixed at the Seattle city limits. It's not very clear to me - if I cross a zone boundary off-peak, do I only pay $2.25, or do I pay $4.50 because I crossed a zone boundary, or what? Even that would be forgivable, though, if not for one massive absence that caught me completely by surprise because I didn't check ahead of time for it, similar to how I don't check ahead of time to make sure the hotel I'd be saying at had an oxygen-nitrogen atmosphere.
There appear to be no day passes on King County Metro.
A King County Metro bus exits the downtown Seattle free ride zone. Based on my reading of the maps, I'm pretty sure that's the southern boundary right there.
During the course of my travels, in Vancouver and Los Angeles and Portland and Chicago and San Francisco, my usual companion has been the unlimited-use day pass, more expensive than a ticket but granting far more flexibility; I don't have to sit down and figure out where I'm going ahead of time and make sure I have enough money to get there, and I don't have to worry about accidentally spending my bus fare. Some places, like Montreal, go further and sell three-day passes to cover out a weekend of use, and the last time I checked Toronto even sold weekly passes, which isn't a common choice.
Not so in Seattle. The only forms of unlimited use passes, so far as I can tell, are regional monthly passes, loaded onto the ORCA electronic farecard and which can provide unlimited monthly use on transit services from Everett to Olympia. No weekly passes, not even any day passes. It is possible to buy books of paper tickets, but as an occasional visitor to Seattle, the idea of laying down $27 for twelve off-peak one-zone tickets is not particularly appealing. But, then, from my point of view, riding the bus in Seattle is not particularly appealing, either. Not when it's a completely unfamiliar system in a completely unfamiliar city, with fare rules that appear to be optimized entirely for people who know exactly where they're going.
Whether it's an out-of-towner or a Seattleite who wants to get a better idea of just where those buses go... it's not exactly the sort of thing that encourages experimentation.