Don't give up -- if you are doing something you really enjoy (and are really good at doing). In that situation, perseverance isn't that hard, and you'll achieve your dreams and goals.
Your best marketing efforts will connect your talents and the things you enjoy with your potential clients. This combination is bound to succeed, over time, because you'll be able to persevere, through easy and challenging situations, as you learn what you need to do to achieve your dreams.
Here is an example from (very) personal experience.
On returning from Africa in 1980, at age 27, I wanted to find the woman of my dreams, settle down, and raise a family. My overseas experience opened the doors to a writing job with the federal government in Ottawa, but didn't solve my real deficiencies in social and personal communications skills.
I'm Jewish, and knew that I wanted to meet a woman of the same faith. So I took my one real skill/talent -- and something I really enjoy doing -- and volunteered to do some writing for the local Jewish newspaper. As I wrote one of my articles, I met a woman who represented a woman's organization. Attractive, yes. We dated, three times. "Let's be friends," she said after the third date.
So we became friends . . . and continued to be friends, year after year.
More than a decade later, in 1991, as my new publishing business went through its first real crisis during the early 1990s recession, I recalled some Brian Tracy tapes about affirmations, "positive self talk" and (most importantly) self responsibility. One day, as all seemed to be lost, I had an insight. "My health is still good, I cannot blame anyone else for my difficulties, and I will do what I can to make things right while accepting total responsibility for my circumstances," I said (out loud) to myself. Then, as I transformed my business, I transformed my outlook on relationships.
A few months later, Vivian suggested that we could go out on a more serious level. Two years later we married. We are still together now, preparing for our 15th anniversary, with Eric at 11 (he has none of my social deficiencies!)
You should never underrate the importance of intelligent perseverance in your business and marketing efforts. The saddest thing you can see is someone with real talent who starts out well, and just quits -- or jumps to something else hoping for a better answer. Usually it doesn't happen. "Intelligent" is an important word -- you should either persevere at the things you do best (for income) and/or which align with your values and dreams. If there are things you enjoy but which you are not great at, carry on -- just do it on your own time, as a volunteer or hobby.
Note in a marketing sense, do not confuse perseverance with becoming an irritating (selling) pest. Some of the saddest situations occur when someone who has played the old 80s sales tapes too often continues calling, again and again, in the hopes of winning business without building a relationship or demonstrating a real meaningful value. You need to respect and understand the needs of the person or organization with whom you wish to work -- and that includes the value of their time and your relevance to them.
In the current economy, you may need some real perseverance and patience -- but you will succeed ultimately if you are really talented at what you do. In the short term, connect that talent to your marketing initiatives; and use it to create/develop your business relationships. (And you can see here how these principals also work really well on a personal level.)