Yes, but it should be limited as should purchased air time. Since they are a fact of life I guess so. The reason is to do anything which allows for a level playing field and less special interests laying money down. But strict rules must be enforced. On honesty the amount of time allowed to attack an opponents record, and equal time must be provided for each candidate.
Equal access allows less corporate driven campaigns to get out there too.
I believe that there should be free time provided for every candidate who runs for office. This will bring about a more informed voter who will be more comfortable in having knowledge about every candidate's stand on issues. Don't get involved with politics if you don't have the money to sponsor yourself. This is a difficult question in that the government does not have the right to confiscate property without fair compensation. Yet, they use the public spectrum to make a living and the government grants this privilege.