as with any business venture there are swings and roundabouts: signing to a label is a marketing and distribution move (+) and a loss of publishing royalties (- to pay for the marketing provided); i.e. the label is signing you to make money for them, not the other way around. Effectively you gain access to their distribution network in return for a percentage of your publishing royalties on everything released on the label - this may or may not be a good deal for you but is most definitely a good deal for them if you are big, even if only for a small amount of time, even on residuals they (or their later purchasers/successors) will still be collecting publishing points 50 years in the future (in perpetuity in fact)....
to make money at every step and minimise your losses you may prefer to create your own label, and access digital distribution networks by using an aggregation service like cd baby
this model was able to work in the 60's and 70's and 80's for Frank Zappa (well before the CD era) because he was prepared to negotiate deals with the major labels for access to their distribution networks for a set fee, rather than a percentage of publishing.