Photos can be converted into a vector file - but there are a few things to consider.
First, you can expect to lose some detail in the photo. Depending on how much detail is lost really depends on how much detail you are starting with. For instance, a low resolution photo will likely lose a lot of detail in the converted vector file - mainly because there wasn't a lot of detail to start with. Even highly detailed photos will lose some degree of detail after the image is converted to vector format.
Second, if the photo is being hand-converted to vector, it will take a lot longer to complete compared to a solid color logo for instance - thus a much higher cost. You can also have a photo "auto converted" by software, but auto converted vector images tend to be converted with undesirable results. There are free and paid auto conversions available online (we do them too), but we don't recommend this method - we consider it a last resort and only an option if you can't afford the hand converted process.
Lastly, when you convert a photo into a vector image, the resulting file will have hundreds, sometimes thousands of shapes and paths. This makes the file very difficult to edit or change once converted. If editing the vector file after conversion isn't needed, then this might not be a problem.
These are the major considerations when converting a raster image (jpg, png, bmp, etc) into a vector image (AI, EPS, SVG, etc).
If you have any questions, feel free to contact us using our support page. Thank you!