Good Morning, FYI no when you increase the size of a logo you must do it with the scalable version which is eps, even for a bilboard or whatever for a big display, then after that you can convert it to a JPG, TIFF or any format depend on what you are going to use.
Some designer sometimes gt only a PICTURE version to do their work which supposed to be (jpg/tiff/png/gif) , so when they need to increase the file it become pixelate and blur also, but never a problem when they have the eps version in hand. This help? :) Hope you understand.
Remain at your disposal for any more info.
Best Regards
Rudy