Depending how you worded your letter you may get a better response than a courtesy letter. If you basically stated "it would be nice to have a bike rack so I may park my bike" I doubt much will happen except for the customary "we'll pass on the information". If you word the letter like they are losing money by a bunch on people on bikes something might be done.

For example: "As Grand Poobah of the bicycle commuter coalition I am writing to inform you about the lack of an adequate bicycle rack at CVS store number XYZ located at so-and-so florida. Members of the bicycle commuter coalition as well as members of the FSU student advocacy bicyle commuter group have been unable to patronize the above stated store due to this delimma. While inconvenient, many members have decided to patronize those stores that provide a simple yet relatively inexpensive bicycle rack. Included in this letter are the prices of different bicycle racks which should prove to be adequate to our members and the community at large. The initial cost of this investment for CVS store #XYZ would pale in comparison to the already lost revenue at this location."

Therefore, if you are an FSU student and a commuter you have not lied one bit .