I work for two small businesses that both have their own e-store websites. I'm speaking to a vendor who produces goods we sell. They provide photos of their merchandise. They have a printed catalog and then an FTP site with jpgs of their photos. Problem is their jpg files on their FTP are pretty tiny. the main product image is a decent resolution 1000x1000 px. 300dpi, but their color swatches are tiny 72x72 100dpi. I told them that they should have their images in TIFF format because its lossless and I have to crop and re-save them as jpeg for website use, which degrades their quality. I also told them their swatches were basically useless due to their size. Their graphics designer got back to me and said Now I agree with the FTP part and TIFF file sizes, they can get pretty big. But the first sentence I have an issue with... 72x72 pixels acceptable? for website use? Please tell me I'm not the only one that disagrees with this statement. I feel that 300x300 is a decent size. Maybe 10 years ago when broadband was not as widespread his statement would make sense to me, but a lot has changed in 10 years.
I agree that 72x72 is way to small in this day and age. However, I also think that 300x300 thumbnails are a little bit too big - remember, more and more people are viewing the web via mobile devices, and large graphics can hinder the experience for those users. 200x200 sounds about right (IMHO) - then perhaps offer a really quick and easy way to zoom the image if the user wants to see more detail.