Or "advertisements" as people in the business like to call them. At yesterday's meeting, the Board of Supervisors narrowly approved an initiative to allow the SFMTA to completely cover Muni buses and trains in advertisements.

Anyone walking down Market Street in the past two years has likely seen the rolling billboards advertising frozen Starbucks beverages or blockbuster movie releases in the past, but the new legislation allows for ads on a greater number of vehicles, as well as ads that cover a larger swath of the vehicle's exterior - including pasting see-through (from the inside anyway) graphics on bus windows.

As the Appeal reminds us today, the expansion of ad space on Muni vehicles was originally projected to bring in a cool $500,000 a year for the agency. However, those numbers might be hard to hit after complaints from the public limited the legislation to just 15 total buses and trains. (The original proposal called for 5 percent of buses and 10 percent of trains to become corporate shills.)

With the 6-5 vote, the supervisors highlighted both sides of the argument wrapped around the advertising issue: On the one hand, David Campos argued that riders would bail on the system if they drag down the (oh-so-pleasant) experience of riding Muni. As Campos explained yesterday, "We want more people to ride. I don’t think it’s a good thing for us to create that kind of experience for them."

On the other hand, Muni is still facing a nasty $22 million deficit and without the additional ad revenue, riders might not even have a bus window to look out of. As Supervisor Elsbernd calmly explained, "if it's a choice of walking 10 extra blocks to my stop, or paying three bucks for that one way ride instead of two, I'll take the obstructed view."