That question can only be answered by taking your goals to a marketing company. As a web marketer we try to understand not just what the prospect is looking to achieve (leads, branding, increased profits, etc.), but by what means they feel is the best way to achieve those goals (social media, content messaging, SEO, etc.) It also helps to know how aggressive they want to tackle it. Most companies understand that despite wanting it all, their budget limitations might prohibit an all-out web market assault.

With these considerations we develop a proposal that we feel will produce a successful web marketing campaign, providing the best value within whatever limitations they set.

In terms of raw numbers, a web marketing campaign itself can be as low as $1000 per month (not very aggressive, even for a small, niche site) up to $10,000 per month, which ultimately may not be aggressive enough for even a large site.