Tomatoes tend to get soggy the longer they ferment. This is due to the acidity of tomatoes. Salt will help keep vegetables that are fermenting firmer and crunchy, so don't skip the salt. This is one of my husband's favorite cultured vegetables and one he will actually make himself. We love to serve this with Tomato Bruschetta, check out the recipe!
Note - It is best to use a starter culture when culturing tomatoes. I have found the salt method doesn't always work as well. These will last a few weeks in the refrigerator.