Did you know you can use social media for polling? Well you can, but it's best to do so only occaisionally. Here's why.
Remember that social media is not about selling stuff or speaking only to customers and prospects about your business. While you may be spending time, effort, and possibly money (via staff resources or third party sources) to keep up with and lead your business efforts and presence on social media, the primary agenda is not business.
Given that reminder, however, once you've established a significant following or friends' list, it's perfectly acceptable and often effective to poll your followers and even to solicit other responses.
If your question is simple and only one-dimensional, e.g., "Do you think mens' ties will be narrower or wider this year?" it's fine to include the question in your post. If you have a more involved poll, survey, or questionnaire, a link to the poll is probably a better idea, though the odds are great your response level will drop off a lot if you require anything that seems like work or requires going to another site.
You might consider offering a prize drawing or a small gift for everyone who completes your poll or survey, and that should up your response rate and, especially if you ask for names and e-mail addresses in the survey, give you more data on potential clientele.
It's worth repeating that you want to use polls, questionnaires, and surveys sparingly - over use them and your responses will suffer. Also, if you are a 'giver' yourself, if you take the time to help others and engage them online, odds are that when you post an occasional survey that your response rate will be much higher.