Regardless of what you want your followers to submit, or what type of image you want them to come up with, using the appropriate hashtag will make a world of difference. Creating a hashtag that is memorable, easy to remember, is not difficult to submit or write and one that people can easily tag are a few factors to keep in mind when holding such competitions.
Not only will it be easier for people to submit their photo, it will also be easier to categorize different images for the RSS feed when they are going to be shared on Facebook or other social media platforms by your business.
Again, keep in mind that hashtags should be business-related. If it has nothing to do with your industry, or if it is something that your followers are going to have a hard time remembering, it is highly likely they are not going to engage in the contest, meaning you will receive fewer entries than you had hoped for. By making the hashtag industry-specific, it allows other people who might not be following your business online, to learn about the contest and to take part in it as well.