Why can some big sellers put listing after listing everyday . On the pet site (birds) you get the same thing every day and its the same

[mark461bird]

Why can some big sellers put listing after listing everyday   . On the pet site (birds) you get the same thing every day  and its the same stuff  they are mostly cages but most look the same to me and there is about fifty of them on a page.They are from the same shop seller .It gets very boring when you are looking for new listings .,.