How to motivate people to participate in a survey, can I include a call for participation in a paper? I am designing a system which is based on text sentences of a specific domain, so that no corpus exists. In order to evaluate, which types of phrases occur, and how often, and to not be biased by my own input, I need theses sentences from other people. Thus, I created a Google forms survey.

Despite posting on relevant mailing lists, offering a significant shopping voucher for a random participant and having my twitter call re-tweeted hundreds of times, I only received about 50 sentences, mostly from my colleagues. While this allows the development to go ahead, I fear that it doesn't give me a picture as accurate I would like of the typical input, especially the rarely used phrases. Also I expect it to negatively impact the credibility of my paper.

My questions:


How can I motivate more people to take part in the survey?
Is it OK to put the URL of the survey in the first paper and hope that this attracts more participants for an improved version later on or is that seen as unwanted advertisement?
Putting a call for participation in a survey in a paper is a bad idea for several reasons:


You would be putting an ephemeral request in an archival publication that people may be reading a decade from now.  That's just plain gauche.
It is likely to be difficult to get appropriate human subjects approvals
Scientists reading your paper are a highly distorted sample population.


As a more effective alternative, may I suggest looking into Amazon Mechanical Turk, which has gained a lot of popularity in recent years as a means of recruiting study participants?