No, it’s not annoying, if done correctly:
If you didn’t message your spouse again that one time after you first met, perhaps you’d never have gotten together.
If you didn’t call your sales prospect again that time after you’d sent them an email full of lovely goodies, perhaps they’d never have been able to benefit from your gift.
If you didn’t offer to solve that problem for that person or company even though they hadn’t asked, perhaps they’d still have that problem. Or worse, they’d have paid twice as much for half a solution.
Sales and marketing should include the gift of pursuit. Not harassment and stalker-tracking and wearing people down…but don’t throw the baby out with the bathwater here: the gift of pursuit is a noble pursuit and a wonderful gift.